Flow Master V7 Release Notes

Flowmaster V7 Gas Turbine R1 Release Notes

February 2008

Flowmaster V7 Gas Turbine R1 A range of new functionality aimed specifically at Gas Turbine applications has been made available with

Flowmaster V7 Turbine Release 1. Users of Flowmaster V7 Turbine R1 will need to obtain a new license

file to access this new functionality. Please contact your Flowmaster representative for details on how to

obtain an appropriate license.

New Capabilities

• Fluid Mixing – Flowmaster V7 Turbine R1 is able to model the mixing of gases or the mixing of

liquids in an analysis. Flowmaster will calculate the fluid properties of the mixture during the

analysis. Flowmaster uses a 'Homogeneous' modelling approach when performing fluid mixing:

i.e. only fluids or gases in a similar fluid state can be mixed. For example, Air can mix with Carbon

Dioxide, but liquids and or gases in different phases cannot be mixed, for example Air and Water.

• Swirl Solver – The Flowmaster V7 Gas Turbine release has integrated a swirl solver into its

analysis capabilities. This solver calculates the swirl generated by rotating parts in a gas turbine

engine and geometrically induced swirl such as preswirl nozzles. The solver also tracks how the

swirl is propagated downstream and how it is either enhanced or degraded by the other

components downstream.

• Swirl represents the portion of the kinetic energy that is attributed to the tangential velocity of the

air flow.

PT = PS + ½ ρ (u2 + v2 + w2)

PT → Total Pressure

PS → Static Pressure

ρ → Density

u → Radial Velocity

v → Tangential Velocity

w → Axial Velocity

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products mentioned herein may be the trademarks of their respective owners. The Flowmaster product is developed and maintained in accordance to the ISO 9001 Quality Standard.


There are 3 different vortices that can occur in these systems. Each of these has a different velocity

profile for the tangential velocity.

• Free Vortex – is a vortex that is not mechanically driven (irrotational). This can occur

between 2 stationary disks that have rotational flow introduced into the chamber. It can

also occur when rotational flow is introduced between two disks spinning at the same

speed. In this case there is no external work done. Any reduction in swirl (tangential

velocity) is converted from kinetic energy to potential energy in the form a static pressure.

The tangential velocity profile for a free vortex is v = k/r

• Forced Vortex – is a vortex that is mechanically driven by a rotating surface. This can

occur with a single rotating disk, multiple rotating disks and counter rotating disks. In

these cases, work is done on the system and there can be either an increase or decrease

in the tangential velocity depending on the direction of the flow. This will result in a

pressure and temperature change in the system. The tangential velocity profile for a

forced vortex is v = kωr

• General Vortex uses the concept of a linear vortex as a semi-empirical hybrid of the free

and forced vortex to represent swirl in real systems where the distinction between free

and forced vortices is less clear.

• Secondary Air – Through the use of complex cavity components and cavity wizard Flowmaster

can utilize the swirl solver to simulate the secondary air systems of gas turbine engines. This is

the air flow through and between the rotating and stationary disks that are attached to the rotor

and stator blades. These swirling flows have a significant affect on the pressures and

temperatures in these rotating cavities. This capability is also flexible enough that it allows

individual companies to customize the software to use their proprietary correlations for the flows

through these rotating passageways.

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New Components

Gas Turbine Components

The following components have been developed particularly for Secondary Air

simulations:

• A Compressible Short Orifice component – to allow for the modelling of

compressible short orifices with either sharp or radiused edges and also allows

for multiple flow paths.

• A Compressible Long Orifice component – to allow for the modelling of

compressible long orifices with either sharp or radiused edges and also allows

for multiple flow paths.

• A Rotating Compressible Short Orifice component – This is similar to the

stationary short orifice with the added feature that one of 4 speeds can be set in

the component. This component is used to model the holes through the

rotating disks of a secondary air system.

• A Rotating Compressible Long Orifice component – This is similar to the

stationary long orifice with the added feature that one of 4 speeds can be set in

the component. This component is used to model the holes through the

rotating disks of a secondary air system.

• A new Discrete Loss component – This component is used to model any

generic loss in a system. In a secondary air system there can be many of the

same losses are repeated in a circular pattern at the same axial position on the

gas turbine. This component allows the user to model many of these losses

with a single component.

• A Compressible Rotating Passage component – For passageways that are

longer than the orifice model can be applied to and those with more complex

rotations. This component is very similar to our pipe component in that it has

options for friction modeling and many options for modeling heat transfer.

Similar to the rotating orifice components it has the 3 global speed options.

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• An Annular Rotating Passage component – Inner Wall Rotating - This

component allows the inner wall to rotate. It is also restricted for axially

symmetric rotation only. This is useful for modeling the flow around the center

shaft of the turbine.

• An Annular Rotating Passage component – Outer Wall Rotating - This

component allows the outer wall to rotate. It is also restricted for axially

symmetric rotation only. This is useful for modeling the flow around the center

shaft of the turbine.

• A new Pressure Source w/ Swirl component – to set an initial value for swirl in

the boundary condition. This is important for models that are only modeling a

portion of the entire system and it is important to know the initial swirl value. It

can be entered either as tangential velocity or Swirl ratio.

• A new Flow Source w/ Swirl component – to set an initial value for swirl in the

boundary condition. This is important for models that are only modeling a

portion of the entire system and it is important to know the initial swirl value. It

can be entered either as tangential velocity or Swirl ratio.

• A new Straight Through Labyrinth Seal component has been developed to

model typical lab seals it is based on Martins formula but has been modified to

provide a global swirl estimation across the whole seal.

• A new Staggered Labyrinth Seal component has been developed to model

typical lab seals it is based on Martins formula but has been modified to provide

a global swirl estimation across the whole seal.

• A new Stair Step Labyrinth Seal component has been developed to model

typical lab seals it is based on Martins formula but has been modified to provide

a global swirl estimation across the whole seal.

• A new User Defined Labyrinth Seal component allows the detailed modelling of

a lab seal by importing the actual geometry of the seal and using the swirl

solver to accurately calculate the swirl and pressure drop.

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• The cavity component is at the heart of the Flowmaster secondary air

capabilities. This component is designed to model the cavities formed by the

rotating and stationary disks of a gas turbine where the secondary rotational

flows become critical.

• The cavity component is actually a specialized composite component that is

used to describe the geometry of the cross-sectional area between the turbine

and stator disks. It evaluates the interaction of the rotating and stationary

geometry swirl that is generated in the component and Flowmaster provides a

specialized wizard to assist in bringing in geometry as well as setting up and

evaluating the cavity component.

• The cell component is where the actual analysis is done within the cavity

component. The cell components are part of a sub-network stored under the

cavity component but each cell component is also made up of many face

components as well.

• The face components are data storage components that are used in

conjunction with the cell components. These components are not active in the

simulation nor do they provide any results. These components contain the

physical attributes of the individual surfaces that make up a cell.

Enhanced Components

• Enhancements to the Compressible Rigid Pipe enable the pipe to model all of Flowmaster’s

compressible heat transfer options.

New Fluids added to the Database The following fluids have been added to the Aerospace Liquids Library to represent common jet fuels:

• Jet A,

• Jet B, and

• Av Gas.

Humid Air fluid properties have been enhanced so that this fluid can be included in a compressible

analysis. 5




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New Tools and Facilities

• New Heat Exchanger Nusselt Number Translator. A new capability called the Nusselt Number

Translator has been developed to convert defined heat exchanger data into dimensionless format.

The Nusselt Number Translator converts test data Inlet Flow rate of hot and air side fluid, Inlet

Temperature of hot and air side fluid and, one of the five Thermal Performance data into Nu v

Re12 & Re34 surface.

• New Loss Data Converter. A new capability called the Loss curve converter has been developed

to convert defined loss data into dimensionless format. The Loss curve converter converts

experimental data like “Pressure Drop (DP) v Volumetric Flow Rate (Q)” or “Pressure Drop (DP) v

Velocity (V)” into “Loss Coefficient (K) v Reynolds number (Re)”.

For further information on each of these capabilities please refer to Flowmaster Help.

Flow Master V7 Release Notes

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