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A two-dimensional model of the aerodynamics of rotor blades in forward flight is proposed in which the motion of the blade is represented by periodical variations of the freestrearn velocity and incidence. A novel implicit methodology for the solution of the compressible Reynolds averaged Navier-Stokes equations and a twoequation model of turbulence is developed. The spatial discretisation is based upon Osher's approximate Riernann solver, while time integration is performed using a Newton-Krylov method. The method is employed to calculate the steady transonic aerodynamics of two supercritical aerofoils and the unsteady aerodynamics of pitching aerofoils. Comparison with experiment and independent calculations for these test cases is satisfactory. Further calculations are performed for the self-excited periodic flow around a biconvex aerofoil. Comparison of quasi-steady and unsteady calculations suggests that the flow instability responsible for the self-excited flow is due to the presence of a shock induced separation bubble in the corresponding steady flow. Finally the method is used to predict the aerodynamics of aerofoils performing inplane and combined inplane-pitching motions. Results show that quasi-steady aerodynamic models are unsuitable at conditions representative of high-speed forward flight. For shock free flows, the unsteady effects of freestrearn oscillations can be represented by a simple phase lag. For transonic flows the influence of unsteadiness on shock wave dynamics is shown to be complex. Calculations for indicial motion show that the unsteady behaviour of the flow is related to the finite time taken by disturbance waves to travel to the shock wave from the leading and trailing edges of the aerofoil

Publisher: Cranfield University

Year: 1999

OAI identifier:
oai:dspace.lib.cranfield.ac.uk:1826/4187

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Cranfield CERES

- 17he effect of an oscillatory fice-swearn-flow on a NACA-4412 profile at large relative amplitudes and low Reynolds numbers',
- (1989). 1kcWAww p --assm prediction using a free wvke. flold ftýc$ mediod',
- 4 -- 'e all) -w-des. Do "slop and asdook*s
- (1980). 4--. -ý9 -j dwee dimensional aerodynamic design of a lifting rotor blade'. Proceedinp of dw 366 Annual Forum a( do American Helicopter Society,
- 4A a Me A b4b resobation appvwb for two aqwdon Unbulance modeHW,
- 9onih bww - -qmý ad dpbrdo model for "parated Uftleat flows',
- A 3-D Chimera grid embedding technique',
- A comparative study of two upwind 1- F-P- as applied to Nmviw4tohm solutions for resolving boundary layers in hypasonic viscous flow',
- (1993). A fbifte volume Euler solver for computing rotarywing aerodynamics on unsnucturcd meshes'.
- A finite difference nudiod. fbr ft cmqmtatlan of it, m, 9 solutions of the equations of fluid dynandcs',
- A model for inhomogencous turbulent flow'.
- A new flux soittinS
- A numerical analysis of the British experimental rotor program blade',
- (1998). A numerical study of dNe tiansonic blade vortex interaction', PbD IMesis, Imperial College, Univenity of Lmxkm.
- A sugsested method of analysing for transonic flutter of control surfaces based upon available experimental evidence,,
- An application of Roes flux difference splitting for k-e turbulence model",
- An efficient method to calculate row flow in hover and forward flight',
- (1987). An Euler solver for calculating the flowfield of a helicopter rotor in hover and forward flight',
- (1988). An experinwntal investigation of pa-WW bla&-vortex interaction for a NACA 00 15 acrofoil',
- (1994). An improved Navier-Stokes/Full potential coupled analysis for fotors',
- (1998). Application of I flow asslyals to holicapin row problems'.
- Application of tw"uation turbulence models in aim-raft desip',
- Approximate Ralmon sohvm psompie va0m ad diffauce schemest,
- (1990). Basic helicopter m
- Calculation of dw A-airfoil using the kT model',
- Computation of rotor blade flows using the Euler equations'.
- Computation of subsonic and transonic flow about lifting rotor blades'.
- Computationd efficiency achieved by time splitting of finite difference openews'.
- Computerized se: 4, yr --I design of a usnoonically qokt bladest
- Conqxvisons of TVD schemes for aubulent uwwnic projectile aerodynamics computations with a two-equation model of turbulence',
- (1997). Coupling of aerodynamic and dynamic methods for the calculation of helicopter rotors in forward flight'. Proiceeffings of the 23d European Rotorcraft Forum,
- CWwW dwoq of m InstdAft avA do mdumian of fluttee,
- (1997). Detailed m ynamic analysis of the RAH-66 FanTail"m using CFD'.
- Development of a aniqW. Wive analysis for rotorcroft",
- (1998). Development of a chinwa unsteady nxtiod for the numarkal sivadation of rotom-raft flowflelds', AMA PVw 98-0421,
- Developnont of a nutnerical andiod solving dw ansleady Bulw Equations for oscillating airfoils'.
- (1998). Dynamics workslwp an rotoe vibratory loads prediction".
- (1956). Equations and procedures for numerically calculating the aerodynamic characteristics of lifting rotors'.
- (1965). Equations do& pz antulents c, m- ij .
- Equations of turbulent motion of an incompressible fluid',
- (1986). Euler calculations for row configurations in unsteady forward flight',
- (1980). Experimental and 11MMMatical studeis on helicopter blade tips at ONERA',
- Experimental boundary layer study on hovering rotors'. 1.
- Flexibility of Euler codes for rotor flows by Chimera techniques',
- (1991). Flowfield analysis of modem helicopter rotors in hover by Navier-Stokes method'. International Technical Specialists Meeting on Rotorcraft Acoustics And Rotor Fluid Dynamics,
- Flowrodd analysis of modem helicopter wtoe in boy= by Naviw.
- (1990). Fluid dynamics for the saidy of Uummic flow'.
- Flux vector splitting for the Ekler equatious'.
- Grid generation for multi-bhWcd rotom and calcualtions with a 3-D code for helicopter rotors in hover'.
- (1997). Helicopter fuselitge aerodynamics under a rotor by Navier-Stokes simulation'.
- (1980). Helicopter theory',
- High speed helicopter research',
- (1983). IEgh resoludon sdlmmm for hyperbolic coon
- (1992). Ihe application of CFD to rifty wing flow probleme,
- (1003). IIURNS: A twee-walm BaladN wkw4tokes nunmical nudW for holkxvw mwW,
- Ile computation of uummic flow through two dimensional gas turbine cascades',
- (1972). Ilia duivation and verification of a new rotor profile on the bask of flow pbmonwm serofoll research and flight tests'. AGARD CP I 11. %"Mdw
- Ilie approximate arithmetical sokdon by finite differencegs of physical problems involving differential equations with an application to the stmsses in a masonry dam'.
- Influence of freesvearn values on k-(o mftlence nko&l predictions'.
- (1990). Introduction to Fluid Dynarnks'.
- (1990). Introduction to traitsonic aerodynamics of aerofbils and wings',
- (1977). Investigation of the transonic flow around oscillating aerofoils,,
- IRIO scowacy TVD schemes Md do k-e equations of butulawev,
- (1994). Irlic foundations of helicopter ftW.
- (1986). lakWon of & maleady BWW equations for fixed and rotor wing --- i N11 m J. Abvndk V&
- (1984). lle prediction of transonic flow on advancing rotors,
- (1972). Madmnatical models of turbulence',
- (1996). Measurement of rotor tip vortices using three-component laser Doppler velocimetry',
- (1971). Medm& of analyzing propellor and fotor boundary layers',
- (1988). Muld-grid solution of the steady FAder equations',
- mW Cbsbavarft SJL. 'Mosodc toftlea flow on$ fbr aisym, afterbodin', AMA F4W 85-IM.
- (1988). Navhr-Stokes cabxkAkm of bovering rotor flowfields'.
- (1996). Navier-Stokes calculation: An industrial tool for air intake optimisation',
- Navier-Stokes correlations of a swept helicopter rotor tip at high alpha',
- Newton tedmique in numerical simulation of turbulent flows'.
- (1991). Numemial solutions of forwardflight rotor flow using an upwind method'.
- (1995). Numerical simulation of imsteady Buler flow around multi-bladed rotor in forward flight using a moving grid approwb',
- Numerical simulation of unsteady Umsonic flows using the Euler equations in integral fom',
- Numerical solution of unsteady rotational flow past fixed and rotary wing configurations'.
- (1983). NunxxkW experiments with the Osher upwind scheme for the Euler equationC.
- (1976). Nurnerical calculation of unsteady trensonic potential flow over helicopter rotor blades'.
- Nurnerical simulation of steady and unsteady Euler flows around multi-bladed helicopter rotors'.
- (1995). Nwne" daimletion of a bovwft rolor using embedded gaids', Praceedinp of the 4e AnMW Bum of dw Amwim Helicopter Society,
- On non4low W md be =odds of ImboboW,
- on the dynandcal theory of I- r- m viscous flulds and the determination of the criterion'.
- On the partial differential equations of mathematical physics'.
- One sided difference approximations for non-linem conservation laws',
- (1993). Pedormwm and rotor load measurements of the Lynx XZ170 helkxow with m; umgulw blades'.
- Plux vector splitting for do Ekder equations'
- (1997). Private conununication.
- Prognm in votor-blade ser 1, ',
- rhmk de recoulesunt twbiUw',
- (1997). Rhmum solvws mkd ownedW olliml fbr flold dýpwniml, Springer-Vedag.
- (1994). Role of Kutta waves on oscillatory shock motion on an airfoil'.
- Rý=mt developnmats in rotor blade sMU',
- SdhW= uwdwd for a bovaring 1-nall, rig row using do Bdw equations's AIAA Popw 854MX IM.
- (1013). Shock waves in the rotor world -a personal perspective of 30 yam of rotor aerodynan-tic developments in the UK',
- (1989). Soludons of the Navier-Stokes equadons for the flow about a rotor blade',
- (1987). Solutions of the Navkv-Stokes equatkma fbr the flow around a rotor blade',
- (1971). Some flight experiments on the MIN Helicopter',
- Sparse Newton nvWW for high resolution schemes',
- Stable and entWy satisfying approximations for tmsonic flow calcWations',
- Subsonic and transonic potential flow over helicopter rotor blades'
- (1972). Subsonic and transonic potential flow over helicopter rotor blades', 1.
- Tber ein neues fal -11-3 jam fIar the --g-lbillipie torbialime,
- (1964). Tfactical computadon of onsoody Hfk'.
- (1951). The lamina boundary layer on a rotating blade',
- The pmdiction of larninarization with a two equation model of turbulence"
- (1992). Tlowfldd of a liftins rotor in hover. A Navier-Stokes simulation'.
- Towards dw ultimate conservative difference scheme V: A second order sequel to Godunovs nxdW',
- Towards the ultimate conservative difference scheme HE Upstream centred finite difference schemes for ideal compressible flow'.
- Transonic aerodynamics of the helicopter rotor', RAe TM (structums)
- (1959). TUM of vMg seeflone.
- Turbulence models for 3D transonic viscous flows',
- Unsteady flow calculations with a multigrid Navier-Stokes method',
- (1982). Upwind differealme sebeam for bypseboW system of conservation laws".
- (1999). Use of a Navier-Stokes code in understanding tilt-rotor flowfields, in hover'.
- Vortex wakes of rotorcraft',
- (1954). Weak solutions of non-linear hyperbolic equations and their numerical computation',
- Zonal two-equation k-4D turbulcom models for w4rodynamic flows,,

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