The RAWAvCon Whole Aircraft Modelling Capability

Richard Wilson

RAW Aviation Consulting Ltd

www.RAWAviationConsulting.com

Personal Experience

• Experience across Industry (Propulsion and Airframe), Research Organisations, Airline and Academia

• Career Highlights

• PhD – Whole Aircraft Design with Laminar Flow

• Aerial Refuelling Systems Study - MRTT

• Trent 1000 selection by Boeing for 787

• Trent 7000 selection by Airbus for A330neo

• Supported Trent 900 (A380) and Trent XWB (A350) development

• Airline visits to remove technical blockages on $1billion sales campaigns

• Rolls-Royce Advance and Ultrafan Concepts definition

• Established RAW Aviation Consulting Ltd

My Whole Aircraft Modelling Experience• 1993-1998 – Cranfield University and DERA

• Modified and deployed ‘Civil’ MVO transport aircraft design synthesis to include Whole Aircraft features of Natural and Hybrid Laminar Flow technologies

• 1998-2017 – Rolls-Royce and Aerospace Technology Institute

• PIANO and Pacelab APD Whole aircraft design codes used in many studies

• Wrote initial APD Specification and comprehensively modified the RR APD data models to include proprietary whole methods

• APD now used by RR, Safran, Saab, ATI, Saab, Bauhaus Luftfahrt, GE might have a copy

• Built ATI’s Whole Aircraft modelling capability around APD using public domain methods

• 2017- Present – RAW Aviation Consulting Ltd

• Customers so far: easyJet, Derwent Aviation Consulting, Rolls-Royce, Cirium (Flight Ascend)

• Partnered with Alton Aviation Consulting for work with a European Flag Carrier and Regional Turboprop operator on aircraft purchasing activities

• RAWAvCon – Bespoke whole aircraft modelling tool developed using public domain methods and data

• RR and easyJet Whole Aircraft work used only tools available to them

Whole Aircraft Design

Level 1: Whole Vehicle AttributesReview existing vehicle capability identifies whole aircraft requirements relative to the market – calibration point for

all design methods for existing

Level 2: Design Synthesis - RAWAvConLower Order Methods based on semi-empirical methods

to rapidly explore design space with full mission performance assessments

Level 3: Detail AnalysisHigh Fidelity Methods (CFD, FEM) used individually or in combination to perform Design of Experiment on new or

challenging features and to realise preliminary design

Detail understanding of the physics that define aerodynamics, structure, systems and propulsion

Requires high detail definition of inputs

Models both optimum and sub-optimal outcomes

What is already been achieved and certificated?How will a new product compete?

Multiple Disciplines assessed at a consistent analysis level

An individual can understand all model disciplines to make technology and architectural studies and decisions

Inputs are major aircraft parameters or technology choicesRapid exploration of the design space including sensitivities

Models only optimum outcome for given aircraft definition

RAWAvCon – IT Requirements

• Excel based – ‘because it is good enough’• Simple linking with any other Excel sheet tools

• Integral and excellent plotting capability

• Used on any mainstream OS I choose to use

• Simple model extension/modification for experimentation/development

• VBA ‘functions’ reduce calculation times

• VBA ‘subs’ permit automation of complex and repetitive performance calculations

• Automated ‘Goal Seek’ function for scaling of wing, fin, stab and engine scale

• Simple migration when methods upgraded – back compatibility assured

RAWAvCon CapabilityAerodynamics Forecast

• Full drag calculation for all flight points based on Aircraft geometrical definition, technology selection and technology trends

• Profile, Lift Induced, Trim and Wave Drag

• Top level aeroelastic representation

• Drag Based on Aircraft Geometry, Technology Choices and Technology Trends

• New Winglet Aerodynamic Method

737NG Winglet Impact on Block Fuel

Underlying chart from APB website

Single Aisle Cruise Drag Spot Point

RAWAvCon CapabilityMass Forecast

• Weights - Component weight build-up• No place for mass fractions

• Wing Weight• Modified Torenbeek LR693 Method

• Enhanced Bending Relief Methods• Winglet Effects• Load Alleviation System• NASA Truss Braced Effect

• Many New Mass Methods• Propulsion System (includes Nacelle)• Fuselage• Individual Systems• Furnishings & Op Items• Landing Gear

• All methods largely based on Aircraft AttributesSingle Aisle Mass Breakdown

RAWAvCon CapabilityEngine Performance Model

• Turbofan Model

• Model based on public domain data plus various course notes

• MTO, MCL, MCT and Idle Rating Thrusts

• SFC Loops defined for part power fuel flow

• Base SFC levels based on public domain technology trends

• Engine Model embedded in Aircraft Model

• Thrust or Fuel Flow calculated as required

• Turboprop Model

• GT modelled with MTO, MCL and MCT thermal power limits

• Propeller and gearbox power limits overlaid

• Propeller model based on basic propeller efficiency model

• Static and low advance ratio flight conditions modelled with standard conceptual methods

RAWAvCon CapabilityMission Performance

• 1st Principles Mission Performance

• Calculation effort focused where flight conditions change

• Multiple limitations respected• Engine Thrust Limits on Cruise Altitude

• Altitude Limits on short missions and Diversions to ensure a minimum cruise distance

• Step Climbs initiated at exact weight where next flight level offers the same fuel mileage (Specific Air Range)

• Payload/Range Modelling

RAWAvCon CapabilityField Performance

• Take-Off Performance

• High Lift Definition and Engine MTO rating definition

• Each Take-Off Calculated from 1st Principles

• Take-Off Speeds Respect

• Minimum VMU:VMCG ratios

• Rapid Rotation defines V2

• Minimum V1:Factored VMU (worst of AEO or OEI)

• V1 optimised to achieve a Balanced Field Length

• VR ≥ V1

• Noise Profiles – Extending the flight trajectory with gear retraction

• Landing

• High Lift System Definition

• Certification Landing Field Length

• Approach Climb Gradient

• Landing Climb Gradient

Each Cross is a Calculation Point

Each Cross is a Calculation Point

RAWAvCon - Less Conventional Airframes

• Hybrid/Blended Wing Body

• Existing Mass Methods• Fin, Powerplant, Pylon, Gear, Winglet,

APU, Air Con, Hydraulic, Electrical, Avionics, Fire Protection, Ice Protections Furnishings, Operator Items

• Modified Mass Methods• Wing, Flight Controls

• New Mass Methods• Centre Body

• Existing Aero Methods

• High-Level S&C Methods

• Existing Powerplant Performance

• Existing Mission Performance

Excel Graphs allow scaling of ‘screen grabs’Underlying images sourced from NASA/CR–2011-216847 Report

RAWAvCon Less Conventional Propulsion

• Boeing V-22 VTOL Modelled• Modified Rotor/Prop Model

• Twin Fin

• Cross shaft weight included

• Hybrid Electric• A321 Parallel Hybrid Modelled and Studied

• High-Level Electric Propulsion Power System Modelled

• Full Performance Modelling Electric Power included

• Turbo-Electric modules

• Turboshaft model with Electric Propulsion Power System

• Distributed Propulsion

• Full Electric• Same basic model as Hybrid Modelling

• Further development when 9-20 seat aircraft considered

Current RAWAvCon Aircraft Database November 2019

Aircraft ModelsA220 – 2 ModelsA300 – 3 ModelsA310 – in workA320 – 15 ModelsA330 – 5 ModelsA340 – 6 ModelsA350 – 6 ModelsA380 – 5 ModelsATR42 – 2 ModelsATR72 – 4 ModelsBAE146 – 1 Model737 – 29 Models747 – 2 In Work757 – 8 Models767 – 5 Models777 – 8 Models787 – 3 Models‘797 NMA’ – 2 Models

Boeing V-22 OspreyBoeing Sugar FreeBoeing Sugar RayCRJ - 3 ModelsDash 8 Q400 – 1 ModelCitationJet – 1 ModelDornier Do328 – 1 ModelEMB145 – 3 ModelEmb EJet – 5 ModelsEmb EJet2 – 3 ModelsG550 – 1 ModelMRJ – 2 ModelsTu-204 – 1 Model

Hybrid Electric Models not included in above counts

• Extensive aircraft model database• … and Growing

• RAWAvCon mission fuel analysis tool created• Mission Performance results extracted from RAWAvCon Design

• Deployed with customers

• Plans to offer access to this capability commercially

• Customer unable to access OEM data

• Target: +/-1% from OEM data (+/-2% worst case)

• Customer feedback on comparison with OEM data

• ‘your results are on the money’

RAWAvCon – Partnering Opportunities

• Design Teams looking for Whole Aircraft knowledge and tools to compliment specialist technical teams

• Specialist researchers seeking to better understand the Whole Aircraft benefits of their technology or idea• Integration of surrogate models into RAWAvCon (customer eyes only) for consistent

level aircraft analysis• Consultation and RAWAvCon Analysis for individual flights or across a route network

• Air Traffic Providers• More representative aircraft trajectories than BADA – freedom to adjust speeds, alt,

etc.• RAW Aviation has a wide understanding of airline operation and weight assumptions

• Environmental Research• Mission or Field Performance assessments.

Simpler IP discussion than with many other partners

Future RAWAvCon Development

• <20 seat Turboprops

• New Mass and Performance Methods

• Electric Propulsion

• Active Laminar Flow Systems

• Method Improvements

• Helicopter

• eVTOL

• Combines Helicopter, <20 Seat Turboprops, Electric Propulsion

Thank You –Questions?

• Coming from RAW Aviation Consulting Q3 2020

• ‘Whole Aircraft Design: So What?’ –Aircraft Design text book

• Approach: Pragmatic, industry based

• Extensive design data for existing and airframe company future designs

• Technology Trends – Improvement vs time

• Extensive use of real-world examples to support text

• Focus on Architectural and Integrated Design – interaction between components and requirements

• Scope: Small Turboprops through to Subsonic Transport Aircraft

• Conventional and Less-Conventional Airframes (H/BWB)

• Conventional and Less-Conventional Propulsion (Electric, Fuel Cell, etc)

Richard Wilson

RAW Aviation Consulting Ltd

www.RAWAviationConsulting.com