DEVELOPMENT OF A VALIDATED DYNAMICS

DEVELOPMENT OF A VALIDATED DYNAMICS MODEL FOR THE STOPROTOR UAV REPORT 2: Rotary Wing Configuration Experimental and Numerical Methods

RMIT Project Code

0200314150

Reference number

RMIT/SAMME/ITS/AVIATION/001-2016

Date of issue

30/04/2016

Dr Matthew Marino (RMIT University – ITS Research Group) Prepared by

Mr Alessandro Gardi (RMIT University – ITS Research Group) Prof Roberto Sabatini (RMIT University – ITS Research Group)

Mrs Deanne Watkins (StopRotor Unmanned Aerial Systems Pty Ltd) Approved by Mr Rowan Watkins (StopRotor Unmanned Aerial Systems Pty Ltd)

SUMMARY This report describes the works performed by RMIT University as contractually agreed with StopRotor Unmanned Aircraft Systems Pty Ltd (project code: 0200314150). This is the second report of a series of three planned deliverables and it details the rotary-wing 6-DOF analytical development and the technical preparation activities performed to carry out, in the subsequent phases of the program, experimental research work in the RMIT industrial wind tunnel and in flight. A suitable form of the aircraft 6DOF model is presented that will be used as a basis for the development of a complete rotary wing 6DOF model for the StopRotor aircraft. The derivatives and coefficients are to be acquired using various engineering methods including: analytical tools, wind tunnel experiments (utilizing the RMIT industrial Wind Tunnel) and experimental flight test. In addition to the 6DOF model for fixed-wing configuration presented in report 1, this report presents preliminary analysis of the main performance parameters relevant to the rotary wing flight phase. Due to the complexity of the full experimental aerodynamic analysis of the StopRotor in its rotary wing configuration, some derivatives will be approximated using the engineering methodologies presented in this report and others will be taken from the wind tunnel experiments. Wind tunnel experiments are more complex than those of the fixed wing configuration. This is mainly due to the rotary wing aerodynamics and the fluids interaction to the surrounding environment. In this case the StopRotor is situated inside a closed wind tunnel. The floor and walls surrounding the StopRotor will significantly influence the flow. As this is a common problem with wind tunnel testing of rotary wing aircraft, suitable correction factors can be applied to account for the influence of these items as described in the report. The post processing of experimental data will require these corrections for an accurate evaluation of the derivatives and coefficients. Scalability is also addressed with insights on how the performance of the StopRotor will change when higher scales are required. Flight test activities are not included currently as they will be part of a successive research collaboration agreement involving the Defence Science Institute, StopRotor Unmanned Aircraft System Pty Ltd and RMIT University.

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TABLE OF CONTENTS 1.

Introduction ................................................................................................................................. 4

2.

Active Milestones ........................................................................................................................ 6

3.

StopRotor Specifications ............................................................................................................ 7

4.

Development of the rotorcraft model .......................................................................................... 9

5.

Numerical approximation of rotorcraft performance................................................................. 10

6.

The RMIT Industrial Wind Tunnel ............................................................................................. 14

7.

Experimental Setup................................................................................................................... 15

8.

9.

7.1

Power Supply .................................................................................................................... 15

7.2

Control System Configuration ........................................................................................... 17

Experimental Methodology and Test Matrix ............................................................................. 19 8.1

Pitot tube calibration.......................................................................................................... 19

8.2

Ground Effect Correction .................................................................................................. 19

8.3

Wall Effect Correction ....................................................................................................... 20

8.4

Advance Ratio Considerations.......................................................................................... 21

8.5

Reynolds Number Dependency ........................................................................................ 22

8.6

Rotor/Operational Ceiling.................................................................................................. 25

8.7

Aerodynamic Test Matrix .................................................................................................. 25

8.8

Repeatability...................................................................................................................... 26

Experimental Preparation Update ............................................................................................ 27

10. Theoretical Framework and Possible Evolutions ..................................................................... 28 10.2

Auxiliary equations ............................................................................................................ 31

10.3

Aerodynamic and propulsive terms .................................................................................. 32

10.4

Linear formulation.............................................................................................................. 35

10.5

Non-linear formulation ....................................................................................................... 36

10.6

Equations for a Point Mass ............................................................................................... 37

10.7

Beyond 6DOFs modelling ................................................................................................. 40

11. Conclusion ................................................................................................................................ 41 12. Nomenclature ............................................................................................................................ 42 References and Bibliography........................................................................................................... 45

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[OMISSIS – Pages 4-44]

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1.

REFERENCES AND BIBLIOGRAPHY

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