Uniiversiità degllii Studii delllla Basiilliicata DOTTORATO DI RICERCA IN Ingegneria Industriale e dell’Innovazione Ciclo XXI Settore scientifico disciplinare di afferenza: _____Ing–ind/08________________ TITOLO TESI Advanced Models for Prediction of High Altitude Aero- Thermal Loads of a Space Re-entry Vehicle Relatore: Candidato: Ch.mo Prof. Aldo Bonfiglioli Raffaele Votta Correlatore: Ch.mo Ing. Antonio Schettino Coordinatore: Ch.mo Prof. V. Magi Triennio 2005-2008 Ad Antonella Nomenclature....................................................................................................................................... 2 Subscripts and Superscripts................................................................................................................. 4 Chapter 1 Introduction ..................................................................................................................... 5 Chapter 2 Space Re-entry Vehicles.................................................................................................. 7 2.1. Reusable Launch Vehicle (RLV): Current Status and On-going Activities .................................................... 7 2.1.1. United States .................................................................................................................................. 8 2.1.2. Europe.......................................................................................................................................... 10 2.1.3. Other Countries............................................................................................................................ 12 2.2. Space Shuttle................................................................................................................................................. 13 2.3. ORION Crew Exploration Vehicle (CEV).................................................................................................... 16 2.4. Unmanned Space Vehicle (USV).................................................................................................................. 20 Chapter 3 Hypersonic Rarefied Flows ........................................................................................... 35 3.1. Hypersonic Flow Regime.............................................................................................................................. 35 3.2. Rarefied Flow and Navier-Stokes Breakdown .............................................................................................. 39 3.3. Basic kinetic Theory and Boltzmann Equation ............................................................................................. 46 3.3.1. The Boltzmann Equation.............................................................................................................. 51 3.3.2. The Moment and Conservation Equations.................................................................................... 57 3.3.3. Accommodation Coefficients....................................................................................................... 60 Chapter 4 Numerical Solutions ...................................................................................................... 62 4.1. Numerical Solution of Transitional Regime - Direct Simulation Monte Carlo (DSMC) .............................. 62 4.2. Solution of Free Molecular Flow .................................................................................................................. 68 4.3. Solution of Continuum Regime – Computational Fluid Dynamics (CFD) ................................................... 70 Chapter 5 Effects of Rarefaction on a Winged Hypersonic Re-entry Vehicle............................... 71 5.1. FTB-X High Altitude Aerodynamic.............................................................................................................. 72 5.1.1. Bridging Formulae ....................................................................................................................... 72 5.1.2. Test Conditions............................................................................................................................. 73 5.1.3. DSMC Results for the Whole Vehicle.......................................................................................... 76 5.1.4. Comparison of the Results from DSMC, CFD and Engineering Methods ................................... 78 5.2. Nose Thermal Analysis ................................................................................................................................. 81 5.2.1. Test Conditions............................................................................................................................. 81 5.2.2. Results.......................................................................................................................................... 82 5.3. Concluding Remarks ..................................................................................................................................... 84 Chapter 6 Local Effects of Rarefaction in Shock Wave Boundary Layer Interactions (SWBLI) ........................................................................................................................ 86 6.1. Shock Wave Boundary Layer Interaction ..................................................................................................... 88 6.2. Results ........................................................................................................................................................... 92 6.2.1. Hollow Cylinder Flare Test Case ................................................................................................. 92 6.2.2. CIRA Plasma Wind Tunnel Test.................................................................................................. 99 6.3. Concluding Remarks ................................................................................................................................... 104 Chapter 7 Orion CEV (Crew Esploration Vehilce): High Altitude Aerothermadynamics................................................................................................... 106 7.1. RTO-RTG043 Working Group ................................................................................................................... 106 7.2. Test Conditions and Results ........................................................................................................................ 108 7.2.1. Grid and Molecular Independence.............................................................................................. 109 7.2.2. Slip Flow Boundary Conditions Validation................................................................................ 110 7.2.3. Results........................................................................................................................................ 112 7.3. Concluding Remarks ................................................................................................................................... 119 Chapter 8 Conclusions ................................................................................................................. 121 References ....................................................................................................................................... 125 1 Nomenclature a = generic extensive variable ac = accommodation coefficient B = magnetic field CD, CL, CS = drag, lift and lateral force coefficients CMx, CMy, CMz = rolling, pitching and yawing moment coefficients c = molecular velocity vector Cf = skin friction coefficient Cp = pressure coefficient; specific heat at constant pressure Cv = specific heat at constant volume D = diameter of the nose Dij = diffusion tensor e = specific energy E = aerodynamic efficiency (E=CL/CD), Electric field f = normalized distribution function in velocity space Fm = Magnetic force F(N) = N particle distribution function F(R) = reduced distribution function F = cumulative distribution function FN = number or real molecules represented by a single DSMC one H = total enthalpy h = altitude, specific enthalpy HTHL = Horizontal Take off and Horizontal Landing K = Thermal conductivity Kn = Knudsen number L = reference length Lx, Ly, Lz = dimensions of FTB-X along the rolling (x), pitching (y) and yawing (z) axes M = Mach number mcs = mean collision separation n = number density nr = number flux 2 N = sampling molecules P = probability, pressure PFA = Projected Frontal Area PND, PNL = parameters defined by Equation 5-3 and Equation 5-4 PPA = Projected Planform Area q (0) = heat flux at the stagnation point Q = molecular quantity r = relative r = position vector RLV = Reusable Launch Vehicle R = gas constant Re = Reynolds number s = stream wise wetted length S = speed ratio SSTO = Single Stage to Orbit TPS = Thermal Protection System St = Stanton number t = time T = temperature u = velocity component in x direction v = velocity component in y direction V = velocity w = velocity component in z direction WA = Wetted Area X, Y, Z = dimensions of the computational domain V = flow velocity, m/s α = angle of attack β = angle of side-slip, reciprocal of most probable speed in an equilibrium gas δ = boundary layer thickness, mean molecular spacing ε = fraction of specular reflection ε0 = dielectric constant of vacuum γ = specific heat ratio λ = free molecule path 3 λε = electrical conductivity tensor ψ = single particle distribution function in phase space, inverse power law ρ = density