Memorial University of Newfoundland ENGI 8926: Mechanical ...

Memorial University of Newfoundland

ENGI 8926: Mechanical Design Project II

Mini Report #2

Vortex Wind Systems

H.A.W.T Rotor Detailed Design

March 7th, 2014

Dan Follett - 200559359

Scott Guilcher - 200915585

Jeremy Tibbo - 200902690

Group M9

Vortex Wind Systems | March 7th, 2014 i

Table of Contents

Table of Figures ............................................................................................................................................. ii

List of Acronyms ........................................................................................................................................... iii

1.0 Introduction ...................................................................................................................................... 1

2.0 Blade Design Theory ......................................................................................................................... 2

2.1 Blade Element/Momentum Theory .............................................................................................. 2

2.2 Iterative process ............................................................................................................................ 4

2.3 Stall Regulated Turbines ............................................................................................................... 5

2.4 Tapered Blade Design ................................................................................................................... 5

3.0 Airfoil Polar Data Evaluation ............................................................................................................. 5

3.1 Airfoil Selection and Evaluation .................................................................................................... 5

3.2 Airfoil Selection Caveats ............................................................................................................... 6

3.3 Root Airfoil S814 ........................................................................................................................... 6

3.4 Mid-Span Airfoil S812 ................................................................................................................... 7

3.5 Tip Airfoil S813 .............................................................................................................................. 8

4.0 Design Considerations....................................................................................................................... 9

4.1 Betz Law ........................................................................................................................................ 9

4.2 Justification for 3 Blades ............................................................................................................... 9

4.3 Theoretical Blade Length ............................................................................................................ 10

4.4 Theoretical Power Output and Demand ..................................................................................... 11

5.0 Blade Design Analysis ...................................................................................................................... 12

5.1 Geometry .................................................................................................................................... 12

5.2 Performance Analysis.................................................................................................................. 13

5.3 Solid Mechanics .......................................................................................................................... 15

6.0 Moving Forward .............................................................................................................................. 18

7.0 Conclusion ....................................................................................................................................... 19

References .................................................................................................................................................. 20

Vortex Wind Systems | March 7th, 2014 ii

Table of Figures

Figure 1 - Sectional Blade Profile [1] ............................................................................................................. 2

Figure 2 - Vector Configuration [2] ............................................................................................................... 2

Figure 3 - Propeller Disc and Stream Tube Area [1] ...................................................................................... 3

Figure 4 - Slipstream Model [2]..................................................................................................................... 3

Figure 5 - S814 Normalized Profile................................................................................................................ 6

Figure 6 - Coefficient of Lift and Drag Ratio vs. Angle of Attack ................................................................... 7


Figure 8 - Coefficient of Lift and Drag Ratio vs. Angle of Attack ................................................................... 8


Figure 10 - Coefficient of Lift and Drag Ratio vs. Angle of Attack ................................................................. 9

Figure 11 - Power Demand Yearly [7][8] ..................................................................................................... 11

Figure 12 - Chord Distribution of Turbine Blade ......................................................................................... 12

Figure 13 - Twist Distribution of Turbine Blade .......................................................................................... 13

Figure 14 - Rotor Power Coefficient for Varying Wind Speeds ................................................................... 14

Figure 15 - Power Curve for Current Wind Turbine Design ........................................................................ 14

Figure 16 - Preliminary Stress Calculation Diagram .................................................................................... 16

Figure 17 – Simplified Blade Dimensions [10] ............................................................................................ 17

Vortex Wind Systems | March 7th, 2014 iii

List of Acronyms

Acronym Meaning

1D One dimensional

2D Two dimensional

3D Three dimensional

HAWT Horizontal Axis Wind Turbine

FEA Finite Element Analysis

Air Density (kg/m3)

Pitch Angle

Difference in Thrust and Lift Direction

Axial Flow Velocity Vector

Sectional Flow of Velocity Vector

Angular Flow Velocity Vector

B Number of Turbine Blades

Change in Momentum Flow Rate

Change in Angular Momentum Rate for Flow x Radius

Lift Coefficient

Drag Coefficient

TSR Tip Speed Ratio

Vortex Wind Systems | March 7th, 2014 1

1.0 Introduction

After performing the Front End Engineering and Design (FEED) work, it became necessary to

evaluate the rotor design of the HAWT in order to continue moving forward in this project. This

report will discuss the detail design of the 500W stall regulated wind turbine blades. The

turbine is to be a robust, reliable and optimal design that would be cost effective for the

application of a small cottage. The reason for targeting the cottage application is an attempt to

supply power to remote, off grid locations. Calculations will be provided in this report to

support the selection of the 500W sizing as the appropriate size turbine to supply sufficient

power to run a radio, television, lights, water pump and potentially fridge as well as water

heater. These are considered basic needs for a cottage and all other larger appliances were left

out of the scope of this project due to the high power demands and ineffectiveness in a cottage

environment.

This report will begin with some background blade design theory. The PropID method of

iteration will be discussed as well as the main theories behind the development of this windows

based program, the blade element and momentum theory.

Using XFLR5 and Prop-ID, Vortex Wind systems was able to design wind turbine blades which

will stall at the regulated power and produce at the average wind speeds found in

Newfoundland for optimal performance. Using XFLR5, the blade airfoils will be first evaluated

then incorporated into PropID to design the optimum blade suitable for the specific design

specifications previously mentioned.

Stress calculations will be provided in this report to gain perspective of what might occur during

future finite element analysis evaluations. Treating the blades as a simple structure, these

calculations are to gain a general idea of what to expect when performing the FEA but are

essential in leading Vortex Wind Systems in the right direction.

This report will discuss why the reasoning behind different design aspects of the blades was

chosen. The reasoning behind the tapered blades, a three bladed turbine design and how the

theoretical blade length was calculated will all be discussed in detail during this report. The

blade design theory section of the report will also describe the iteration method PropID uses to

determine the necessary outputs needed to design the blade.

To conclude the report, Vortex Wind Systems will specify the steps moving forward in the

coming months to ensure the proper closure of the project.


2.0 Blade Design Theory

2.1 Blade Element/Momentum Theory

In considering our blade design Vortex Wind Systems chose to utilize Prop-ID for the design and

analysis of the turbine blade. Blade element and momentum theory are used in predicting the

performance parameters and are the supporting theories behind the Prop-ID software package.

Blade element and momentum theory involve the division of the blade into multiple sections

while lift, drag, thrust and torque are represented in a two dimensional plane as illustrated in

Figure 1 - Sectional Blade Profile Figure 1.

Figure 1 - Sectional Blade Profile [1]

In addition, axial and angular momentum is applied to the model producing a non-linear set of

relationships.

Figure 2 - Vector Configuration [2]


By analyzing both circumferential and axial directions, the governing principle behind the

conservation of flow momentum can be analyzed. It is by the consideration of momentum

theory that the change in flow momentum in the axial direction can be observed. This means

that any change in flow momentum observed upstream that subsequently passes through the

blade must in turn equal the thrust produced by this element of the blade. [3]

Figure 3 - Propeller Disc and Stream Tube Area [1]

In an effort to eliminate any unsteady effects resulting from our blades rotation, it is assumed

the horizontal axis wind turbine (HAWT) is covered around its sweep area as shown below in a

slipstream model.

Figure 4 - Slipstream Model [2]


2.2 Iterative process

Equations [2]

1 -

2 –

3 -

4 -

5 -

6 -

The iterative process that Prop-ID uses to better define various desirable properties begins with

some initial guess inflow factors. These inflow factors are then used to find the flow velocity

and flow angle on the blade as shown in equations 3 and 4. This is then used to determine

blade section properties to in turn estimate the thrust and torque as shown in equations 1 and

2.

With these approximations in place equations 5 and 6 can be used to better define the values

of the initial inflow factors. This process in executed repeatedly until the inflow factors have

converged within an acceptable tolerance.

In using the Prop-ID software package this iterative process can be repeated continually until a

value for both thrust and torque can be predicted for the overall performance.

Some limitations to the theory and through association the software Prop-ID include:

Negates 3D Flow Velocities

Over Predicts Thrust

Under Predicts Torque

Overshoots Actual Efficiency by 5-10%

The objective is to use this software to create comparative results considering environmental

conditions. In turn these comparative results act as a tool to help optimize the blade pitch given

the rated wind speed in addition to optimizing our blade solidity aiding in the material selection

process.


2.3 Stall Regulated Turbines

Constant-speed, stall-regulated wind turbines have blade designs that passively regulate the

produced power. The fixed-pitch blades are designed to operate near the optimal tip speed and

lift to drag ratio at low wind speeds. When the wind speed increases, the angle of attack

increases and parts of the blade, starting at the blade root, begin to enter the stall region. [4] As

blades move into a stall region they begin to produce less lift, reducing the tip speed and power

output. A stall controlled blade will not spin at excessively high rates and damage the turbine.

This is a main design focus for Vortex Wind Systems.

2.4 Tapered Blade Design

Blades which are designed for optimum power production will have a tapered blade design

with an increasingly larger cross section at the root of the blade and much smaller at the tip of

the blade. The pressure on the suction side of the blade is lower than the pressure side;

therefore the air will flow around the tip from the lower toward the upper side. This reduces

the lift of the blade and decreases the power production near the tip of the blade. With a

tapered blade design moving from a larger cross section at the root, to a smaller cross section

at the tip, these tip loss effects can be reduced [4]. A tapered blade design will be utilized by

Vortex Wind in attempt to maximize the power output.

3.0 Airfoil Polar Data Evaluation

3.1 Airfoil Selection and Evaluation

The properties of incoming wind vary when moving radially along the blade section from root

to tip. That is, the root blade section experiences lower relative wind speeds than the tip due to

its position from the center. The profile of an airfoil dictates the aerodynamic properties of the

blade and is critical in designing and evaluating the turbine. For this reason, the blade is

sectioned into three distinct regions: the root, mid-span, and tip. Three airfoils were selected

for these regions. An analysis of their lift and drag data across varying angle of attacks and a

range of Reynolds numbers were conducted using the XFLR5 program for the integration into

Prop-ID.


3.2 Airfoil Selection Caveats

It should be noted that Prop-ID requires the lift and drag data to be evaluated up to an angle of

attack of 27.5°. While angles this high may not be present in the design, the program will not

operate without data in this region. As a result, some airfoils cannot be selected as it is not

possible to calculate data with the XFLR5 program. The airfoils selected are recommended for

wind turbines and all reached converged solutions for the required range.

3.3 Root Airfoil S814

The S814 airfoil, shown in Figure 5, is specifically designed to operate in the root region of the

blade. The primary purpose of its design is to create high maximum lift and low drag for the

lower airspeed region. This profile also has a thicker cross-section to provide greater strength to

the blade structure. The profile coordinate data was directly imported into XFLR5 where a

batch analysis was completed to obtain comprehensive lift and drag information suitable for

integration into Prop-ID.

Figure 5 - S814 Normalized Profile

Figure 6 shows the lift and drag ratio for a series of Reynolds numbers across a range of angles

of attack. This plot shows the set of attack angles where the foil can productively capture wind

energy. The pitching moment coefficient plot and a lift versus drag plot for this foil were also

completed and are contained in Appendix A1.


Figure 6 - Coefficient of Lift and Drag Ratio vs. Angle of Attack

3.4 Mid-Span Airfoil S812

The mid-span section of the airfoil is considered to be the main power generating section of the

blade [4]. Its profile can be seen in Figure 7. A higher lift to drag ratio is desired for the range to

attack angles it is to be operating, this is observed in Figure 8. The pitching moment coefficient

plot and a lift versus drag plot for this foil were completed and are contained in Appendix A1.




3.5 Tip Airfoil S813

The highest relative wind velocities occur in the tip section of the blade. As the relative angle of

attack increases with an increasing wind velocity, this section of the blade experiences the

highest drag forces. Minimizing the effects of drag is the primary consideration for the foil [5].

The profile can be seen in Figure 9 and drag ratio in Figure 10. The pitching moment coefficient

plot and a lift versus drag plot for this foil were completed and are contained in Appendix A1.




4.0 Design Considerations

4.1 Betz Law

Betz Law states that the design can only convert approximately 59% of kinetic wind energy into

mechanical energy. Efficiency is determined by the rotor blade where the maximum efficiency

is maintained at the optimal rotational speed (aerodynamic power coefficient) for the given

blade.

In generators, when converting rotational mechanical to electric energy the resistance to the

rotor provides a form of friction that can only be overcome with a specific start up wind speed

that must be reached to overcome these forces.

Another source of inefficiency is when yawing each blade experiences cyclic loading at its root

depending on its position. These loads combined with the drive train shaft can be balanced

symmetrically for three blades yielding a smoother operation for turbine yaw [4].

4.2 Justification for 3 Blades

In considering the number of blades and the optimization of the model, aerodynamic efficiency,

component costs and system reliability need to be taken into account. Aerodynamic efficiency

increases by 6% [4] when moving from one to two blades, while moving from two to three

blades provides an increase of 3% [4]. Any additional blades beyond three provide minimal


returns in efficiency. In addition, as the blades would need to be much thinner and unstable

causing interference with the tower; it sacrifices too much blade stiffness when considering

interference with the tower. Adding additional blades would also lead to a higher

manufacturing cost and would decrease the overall rotational speed. Fewer blades with higher

rotational speeds result in reduced peak torques in the drive train lessening the probability of

gearbox and generator failure.

4.3 Theoretical Blade Length

[5]

Power Output – 500W

PC - Power Coefficient (Efficiency of the rotor to convert energy) (35%)

A - Sweep Area of the Blade ( (Units in )

r – Radius of Sweep Area (Units in m)

PA - Power Density of the Wind = 0.6125x (S - Wind Speed in m/s)

G - Generator Efficiency (90%)

With the output and rated wind speed taken from out market analysis, solving for r to get the

following:

r = 1.202 m

This gives an initial guess from which to compare with the Prop-ID model. Appendix A2 contains

detailed calculations.


4.4 Theoretical Power Output and Demand

In maintaining an average run time of 66%, a theoretical power output both in Watts (W) and

Kilowatt Hours (kWhrs) for the turbine per year can be estimated. This can then be used for

various comparisons. Calculations for the following section are included in Appendix A2.

The yearly kWhrs for Vortex Wind System’s 500W wind turbine is found to be which 2851.2

kWhrs/year at 66% operation time [6]. At this kWhr output a 500W device at this kWhr output

will have 5702.4 hours per year. Taking the hours per year of operation and applying it to a

500W generator at 4.2 liters of fuel for 5.8 hours of operation yields a total of 4129.3 liters per

year [7]. From the current gas prices ($1.35 per liter) it would cost $5,574.00 to run a generator

for the equivalent output per year [8].

These are rough calculations but with an expected life of around twenty years and an estimated

price tag of $500-$1500 as found in the market analysis, the financial benefits of using a

horizontal axis wind turbine add the primary source of energy are evident even during the first

year.

Considering power consumption, the daily kWhr usage rates for the appliances below for the

associated average usage length trends are provided [8] [9].

Figure 11 - Power Demand Yearly [7][8]

It can be seen from the above summation that at 26.4 kWhrs per day for 52 weekends per year

that the 2745.6 kWhrs/year power demands falls just below the estimated output of 2851.2

kWhrs/year.


5.0 Blade Design Analysis

5.1 Geometry

The variables assessed for the geometric design and optimization within Prop-ID are: rotor

diameter, chord length, twist and pitch. An initial geometry with preliminary values was

entered as a starting point for the programs iteration methods. To perform the analysis, a

preliminary design point was specified. The required 500W output with a target wind speed of

7m/s was used. Using data from the market analysis, the HAWT was set to operate at 300 rpm,

comparable to existing designs. Aerodynamic data calculated from the family airfoils discussed

was integrated into Prop-ID. The S814 airfoil was set to exist at the first 30% of the blade

length, S812 from 30% to70%, and S813 for the remainder of the blade. Applying this design

point to the base geometry, with the integrated foil data, Prop-ID functions were executed to

manipulate the rotor radius, and chord lengths to reach the specified design point.

Prop-ID concluded that the optimal rotor radius to meet the design point with the given airfoil

data was 4.3 feet. This is a realistic result as the simplified initial calculations expected a radius

of 3.9 feet. Figure 12 illustrates the optimized chord length across the new length of the blade.

This plot shows the tapering of the chord expected of this type of airfoil.

Figure 12 - Chord Distribution of Turbine Blade


Figure 13 (twist distribution for the blade) follows the typical profile for a stall regulated

turbine; however, these angles need further optimization as the functions for this procedure

have not yet been successfully run. The twist angles shown represent a typical distribution of

this class of turbine [5] Input and output geometry files can be seen in Appendix 3.

Figure 13 - Twist Distribution of Turbine Blade

5.2 Performance Analysis

From the results of the geometric analysis, the 2D-Sweep and 1D-Sweep functions were used to

perform an analysis on the rotor performance and aerodynamic characteristic of the blade.

Figure 14 shows that the maximum rotor power coefficient of 46% to occur at 5.6m/s and the

target wind speed of 7 m/s to have an efficiency of 39%. Ideally the peak efficiency should

occur at the target wind speed to maximize the energy captured as wind at 5 m/s does not hold

a significant amount of harvestable energy as illustrated in the Power Curve of Figure 15.


Figure 14 - Rotor Power Coefficient for Varying Wind Speeds

The target is to design the blades to produce 500W at a wind speed of 7 m/s, but the turbine

has an estimated 497 W peak power production at 9.8 m/s. At 7m/s it is estimated that power

production is 415W, 17% lower than required. Further optimization of the design parameters

will be necessary to shift the power curve into the correct position. It is evident that after peak

power is reached, power efficiency and production decrease as wind speeds continue to

increase – this is the result of stall regulation. The power curve does continue to climb but does

not achieve comparable production at high wind speeds.

Figure 15 - Power Curve for Current Wind Turbine Design

0.000

0.100

0.200

0.300

0.400

0.500

0 5 10 15 20 25 Ro

tor

Po

we

r C

oe

ffic

ien

t

Wind Speed (m/s)

Cp vs. Wind Speed


The tip speed ratio (TSR) is the fraction between the tip speed of the blade and the wind speed.

The TSR versus rotor power coefficient plot shows the range of tip speeds observed by the

blade. Peak efficiency is achieved with a tip speed ratio 6.98 but values of as high as 15 are

seen. Values above 10 are considered high and consideration should be given to centripetal

effects and potential fouling of the blade at the leading edge. Further optimization should

attempt to reduce high TSR values and minimize any detrimental effects.

5.3 Solid Mechanics

Before performing a finite element analysis (FEA) on the actual blade design, it was decided to

perform preliminary stress calculations. This is to gain an approximate estimate of values and to

give a starting point for the finite element analysis evaluation which will be performed in the

coming months. The first step to finding a rough maximum stress value is calculating the lift and

drag forces that will occur on the blade. The maximum coefficient of lift (CL) as specified from

Prop-ID is 1.6 while the maximum coefficient of drag (Cd) was found to be 0.39. These values

are directly proportional to their respective lift and drag forces. The lift and drag forces were

solved using the following formulas:

(Lift Force per unit length) [4]

(Drag force per unit length) [4]

Where:

Ρ = density of air (1.225 kg/m3)

U = wind speed (12.5 m/s)

c = chord length (0.22552 m)

This yielded the following lift and drag forces:

The blade has been modeled as a uniform beam cross section which is fixed at one end as

shown in Figure 16Figure 16. Using the distributed loads (Lift and Drag) previously calculated we

can gain a rough estimate of the stresses at the root of the blade. The width and height values

of the beam simulate the initial size of a spar like beam which will run the length of the beam to


act as support for the outer layer. Here it is assumed that this beam will take all of the force

due to lift and drag.

Figure 16 - Preliminary Stress Calculation Diagram

Two moments will occur in this stress evaluation. A moment will occur about the Y-axis in a

negative manner, while a second moment will occur about the Z- axis in the positive direction.

These are calculated by:

This yields a Mz = 7.16 Nm and My = -29.38 Nm. Now the moments the maximum stress can be

evaluated using the simplified equation below:

Solving this expression yields a maximum stress of 1.297 MPa. Using similar equations, an

analysis was performed in the event the blades are parked and winds reach 160 km/h. Here the

blades were assumed to be flat plates with the wind acting perpendicular to the blade surface.

The maximum stress at this point was found to be 18.4 MPa. This will be the value we will

use moving forward as it is worst case scenario and Vortex Wind Systems believes that


designing to suit these stress values will provide safe operation of the turbine. For more

information on these calculations please refer to Appendix A2.

It is also important to understand the centripetal force. This is an external force that is required

to make a body follow a curved path. This force acts inwards, towards the centre of curvature

of the path. Figure 17 shows the simplified blade dimensions used in this analysis.

Figure 17 – Simplified Blade Dimensions [10]

The centripetal force can be calculated by:

[10]

The area will be an estimation of the area of the airfoil at the root section of the blade. The

rotations per minute (rpm) used is the design rpm which will be the maximum. This is to gain

rough estimate of values and to give a starting point for the finite element analysis evaluation

which will be performed in the coming months. In this case:

A = 1.17x10-2 m

ρ = 1.225 kg/m3

r2 = 1.46 m

r1 = 0.15 m

= 31.41 rad/s


This gives a centripetal force of the blade is found to be F = 14.9 N. So as stated previously the

force due to max winds and assuming the blades are stationary will be used to move forward

with a rough estimate to begin FEA.

6.0 Moving Forward

At this point, Vortex Wind Systems is ready to move forward to the final section of the Detailed

Design phase which consists of the design of the various components needed for the

prototyping and testing of the turbine. It has been decided that testing will be done at a scaled

version of the actual design and tested in the wind tunnel provided for student use at Memorial

University of Newfoundland. In order for the testing to be completed the following components

will need to be fabricated:

Turbine Blades (3)

Shaft to connect blades to generator

Turbine main frame

Rotor hub

Design analysis will be conducted for the design of the shaft to ensure that it can withstand the

expected forces during testing. However a detailed finite element analysis will not be

performed due to time constraints. The top priority of the project is the design of the blades, so

a finite element analysis will be performed moving forward to select an appropriate material

for the blades. The following components will be bought and will not be designed in the same

manner as the previous items:

Generator

Bearings for shaft

After the design of the prototype, testing will be conducted and the final report will summarize

the work performed throughout the entire project as well as the work done in testing to

compare the theoretical power curve as found in PROP-ID and the power curve found during

testing exercises.


7.0 Conclusion

Due to the inexperience of using Prop-ID, the learning curve proved to be more complex than

initially expected. However with persistence, Prop-ID and XFLR5 have been used to develop an

initial blade design that we can now evaluate and continue optimizing if necessary. Vortex Wind

solutions is content with the power curve produced and it is believed that this can be optimized

if need be. It is now important to compare the power curve produced to other curves in the

industry to assess whether or not the design goal of producing more power than competitors

with Newfoundland wind trends was achieved.

Vortex Wind Systems has now made initial stress calculations and will now continue on to

ensure the strength of the blades by performing a thorough finite element analysis. The

maximum stress that will be used as a starting point for selecting material will be 18.4

MPa, which was calculated at wind speeds of 160 km/h and assuming the blades were acting as

flat plates with the wind force acting perpendicular to the surface. This would be a rare case

but to ensure the safety and reliability of the blades it has been decided to move forward with

this value.

As described in the report the blade consists of a tapered cross section to limit the tip loss

effects on the blades. Also three blades were chosen to optimize the efficiency of the turbine.

Now that the detailed design is completed, prototyping, testing and finite element analysis of

the blades will be carried out in the next month of the project. A large portion of detail will be

put forward in the finite elemet analysis as the blades are the main focus of this design process.

At this point Vortex Wind Systems has remained on schedule according to the project

management plan and will attempt to remain this way for the last month of the project.


References

[1] D. M. Cavcar, "http://home.anadolu.edu.tr/~mcavcar/hyo403/Blade_Element_Theory.pdf,"

Anadolu University, School of Civil Aviation , 2004. [Online]. [Accessed 2014].

[2] "Multidisciplinary Design Project," University of Sydney, 1996-2006. [Online]. Available:

http://www-

mdp.eng.cam.ac.uk/web/library/enginfo/aerothermal_dvd_only/aero/propeller/prop1.html.

[3] D. D. Symons,

"http://www2.eng.cam.ac.uk/~hemh/climate/P8_Blade_Design_Student_Handout_2009.pdf

," [Online]. [Accessed 2014].

[4] J. F. Manwell, J. G. Mcgowan and A. L. Rogers, Wind Energy Explained 2ed, Chichester: John

Wiley & Sons Ltd., 2009.

[5] J. McCosker, "Design and Optimization of a Small Wind Turbine," Rensselaer Polytechnic

Institute, Hartford, 2012.

[6] "Wind Measurement International," [Online]. Available:

http://www.windmeasurementinternational.com/wind-turbines/om-turbines.php.

[Accessed 2014].

[7] "Alibaba," [Online]. Available: http://micfull.en.alibaba.com/product/636072013-

209804414/Mini_portable_gasoline_generator_500w_4_stroke_with_CE_ISO_EPA.html.

[Accessed 2014].

[8] "Concordia Electric Cooperative Inc," [Online]. Available:

http://www.concordiaelectric.com/forms/kWh_Usage.pdf. [Accessed 2014].

[9] "Festival Hydro," [Online]. Available:

http://www.festivalhydro.com/index.php/electric/appliance-power-use. [Accessed 2014].

[10] T. R. A. o. Engineering, "Forces on Large Steam Turbine Blades," [Online]. Available:

https://www.raeng.org.uk/education/diploma/maths/pdf/exemplars_advanced/22_Blade_F

orces.pdf. [Accessed 2014].


[11] "Flap Turbine," [Online]. Available: http://www.flapturbine.com/how_many_blade.html.

[Accessed 2014].

[12] "Newfoundland Gas Price," [Online]. Available: http://www.newfoundlandgasprices.com/.

[Accessed 2014].

Vortex Wind Systems | March 7th, 2014 iV

Appendix A1

Figure A2.1 - Cl Vs. Alpha S812



Figure A2.4 - Cl Vs. Cd S812

Figure A2.7 - Cm Vs. Alpha S812



Figure A2.9 – Cl Vs. Alpha Prop-ID Blade Segments

Vortex Wind Systems | March 7th, 2014 V

Appendix A2

Vortex Wind Systems | March 7th, 2014 Vi

Appendix A3

PROP-ID Input file # Stall Regulated Turbine 500W Input File # Basic input MODE 1.0 # wind turbine INCV 0.0 # wind turbine mode LTIP 1.0 # use tip loss model LHUB 1.0 # use hub loss model IBR 1.0 # use brake state model ISTL 1.0 # use viterna stall model USEAP 1.0 # use swirl suppression WEXP 0.0 # boundary layer wind exponent NS_NSEC 10.0 1.0 # number of blade elements/number of sectors IS1 1.0 # first segment used in analysis IS2 10.0 # last segment used in analysis BE_DATA 1 # printout blade element data SH 0.0 # shaft tilt effects RHO 0.0023769 # air density (slug/ft^3) # Geometry HUB 0.04 # normalized hub cutout HH 3.333 # normalized hub height BN 3 # blade number CONE 0 # cone angle of rotor (deg) RD 4.279492 # radius(ft) CH_TW # Normalized chord and twist distribution 0.172918 13.0000 0.155626 8.0000 0.103751 6.0000 0.086459 6.0000 0.064258 4.0000 0.056225 1.0000 0.064258 -1.0000 0.056225 -3.0000 0.048193 -4.0000 0.043229 -5.0000 AIRFOIL_MODE 4 4 s814.pd .24 13. 3 1.600 6 s814.pd .24 13. 3 1.600 6 s812.pd .21 14.3 3 1.180 6 s813.pd .16 9. 3 1.100 6

# airfoil family 1 with 2 airfoils # r/R-location and airfoil index AIRFOIL_FAMILY 4 0000 1 .3000 2 .7500 3 1.0000 4 USE_AIRFOIL_FAMILY 1 # Enforce tip loss model to always be on TIPON # Use the Prandtl tip loss model, # not the original modified model. TIPMODE 2 # Design point: 300rpm, 2 deg pitch, 16 mph DP 1 300 2 16 2 #Specify the peak power (500W) and iterate on the rotor scale NEWT1ISWP 300 0.50 1 40 .1 1 1 999 1 7 999 .3 IDES # Specify the peak power (500W) and iterate on the chord #NEWT1ISWP 300 0.5 1 25 .1 1 1 999 2 1 999 .05 #IDES #NEWT1ISWP 300 0.5 1 25 .1 1 1 999 3 2 999 #IDES #NEWT1ISWP 300 0.5 1 25 .1 1 1 999 3 3 999 #IDES #NEWT1ISWP 300 0.5 1 25 .1 1 1 999 3 4 999 #IDES #NEWT1ISWP 300 0.5 1 25 .1 1 1 999 3 5 999 #IDES #NEWT1ISWP 300 0.5 1 25 .1 1 1 999 3 6 999 #IDES #NEWT1ISWP 300 0.5 1 25 .1 1 1 999 3 7 999 #IDES #NEWT1ISWP 300 0.5 1 25 .1 1 1 999 3 8 999 #IDES #NEWT1ISWP 300 0.5 1 25 .1 1 1 999 3 9 999 #IDES #NEWT1ISWP 300 0.5 1 25 .1 1 1 999 3 10 999 # Initiate design (does some required preliminary work before analysis) #IDES

# Determine the rotor power, Cp, and thrust curves (2D_SWEEP) # # use pitch setting from design point (DP) 1 PITCH_DP 1 # use rpm from design point (DP) 1 RPM_DP 1 # sweep the wind from 5 to 50 mph in increments of 1 mph WIND_SWEEP 1 50 1 2 # perform the sweep 2D_SWEEP # write out data to files # 40 - power curve (kW) vs wind speed (mph) # 45 - Cp vs TSR # 51 - rotor thrust curve WRITE_FILES 40 45 51 # Compute the gross annual energy production # Output the data to file: gaep.dat # # Initial avg wind speed - 14 mph # Final avg wind speed - 18 mph # Step - 2 mph # Cutout - 45 mph # # 100% efficiency # GAEP 14 16 .2 45 # # 15 mph only, 85% efficiency GAEP 14 16 1 45 .85 Report_Start # Report the last GAEP analysis case REPORT_SPECIAL 8 999 999 REPORT_END # Obtain aero distributions along the blade (1D_SWEEP) # PITCH_DP 1 RPM_DP 1 WIND_SWEEP 5 30 5 2 1D_SWEEP # write out # 75 - blade l/d dist # 76 - blade Re dist # 80 - blade alfa dist # 85 - blade cl dist # 90 - blade a dist WRITE_FILES 75 76 80 85 90

# Write out # 95 - chord dist (ft-ft) # 99 - alfa dist (ft-deg) WRITE_FILES 95 99 #REPORT_BE_DATA 14 0 #REPORT_BE_DATA 14 .25 #REPORT_BE_DATA 14 .5 #REPORT_BE_DATA 14 .75 # Write out the rotor design parameters to file ftn021.dat DUMP_PROPID *

Prop-ID Geometry Output File RHO 0.002377 HUB 0.034584 RD 4.279492 CH_TW 0.172918 13.0000 0.155626 8.0000 0.103751 6.0000 0.086459 6.0000 0.064258 4.0000 0.056225 1.0000 0.064258 -1.0000 0.056225 -3.0000 0.048193 -4.0000 0.043229 -5.0000 AIRFOIL_MODE 4 4 s814.pd 0.240 13.000 3.000 s814.pd 0.240 13.000 3.000 s812.pd 0.210 14.300 3.000 s813.pd 0.160 9.000 3.000 AIRFOIL_FAMILY 4 0.0000 1 1.0000 0.3000 2 0.7000 0.7500 3 0.2500 1.0000 4 0.0000 USE_AIRFOIL_FAMILY 1 DP 1 250.0000 2.000 16.000 2

Memorial University of Newfoundland ENGI 8926: Mechanical ...

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