Assessment of Rarefied Hypersonic Aerodynamics Modeling and Windtunnel Data

Padilla, Jose F.; Boyd, Iain D.

doi:10.2514/6.2006-3390

Cited by 17 publications

(12 citation statements)

References 12 publications

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“…Figures 19a and 19b show comparisons for aerodynamic properties between measurement and simulation. In these figures, "FMF" shows results obtained from free molecular theory, and "MN" indicates modified Newtonian theory [67]. For both the drag and the pitching moment, the 3-D DSMC computations are in excellent agreement with the measured data.…”

Section: A Analyses Of Hypersonic Laboratory Experimentssupporting

confidence: 66%

“…The comparisons also show that neither the free molecular theory nor the Newtonian theory provide any useful results for this condition, indicating that the more computationally expensive DSMC approach is required. Figures 20 and 21 show the corresponding results for Mach 10 flow of nitrogen over a model of the Apollo Command Module capsule at a Knudsen number of 0.067 conducted in the exact same facility as the cone studies [67]. In this case, significant differences between simulation and measurement are found for the drag force.…”

Section: A Analyses Of Hypersonic Laboratory Experimentsmentioning

confidence: 85%

“…A variety of very small models were tested that included cones as well as capsules such as Apollo, Gemini, and Mercury. The MONACO DSMC code [14] was applied to simulate the tests on the cones that were conducted in a Mach 10 flow of nitrogen at a global Knudsen number of 0.065 [67]. Figure 18 shows contours of Mach number computed for an angle of attack of 20 deg.…”

Section: A Analyses Of Hypersonic Laboratory Experimentsmentioning

confidence: 99%

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Computation of Hypersonic Flows Using the Direct Simulation Monte Carlo Method

Boyd

2015

Journal of Spacecraft and Rockets

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The direct simulation Monte Carlo method has evolved over 50 years into a powerful numerical technique for the computation of complex, nonequilibrium gas flows. In this context, "nonequilibrium" means that the velocity distribution function is not in an equilibrium form due to a low number of intermolecular collisions within a fluid element. In hypersonic flow, nonequilibrium conditions occur at high altitude and in regions of flowfields with small length scales. In this paper, the theoretical basis of the direct simulation Monte Carlo technique is discussed. In addition, the methods used in direct simulation Monte Carlo are described for simulation of high-temperature, real gas effects and gas-surface interactions. Several examples of the application of direct simulation Monte Carlo to flows around blunt hypersonic vehicles are presented to illustrate current capabilities. Areas are highlighted where further research on the direct simulation Monte Carlo technique is required. Nomenclature A= surface element of area, m 2 C = particle velocity vector, m∕s e r = specific rotational energy, J∕kg f = probability density function g = relative velocity, m∕s Kn = Knudsen number k = Boltzmann's constant, J∕kg L = characteristic length scale, m m = mass of a particle, kg N = average number of particles in a cell N p = number of particles in a cell N t = number of iterations n = number density, m −3 P c = collision probability r = particle position vector, m T = temperature, K t = time, s V = cell volume, m 3 Δf = rate of change due to collision processes ε act = activation energy, J ε r = rotational energy, J ε tot = total collision energy, J λ = mean free path, m ζ = number of rotational degrees of freedom σ = collision cross section, m 2 τ r = rotational relaxation time, s ω = viscosity temperature exponent

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Section: A Analyses Of Hypersonic Laboratory Experimentssupporting

confidence: 66%

Section: A Analyses Of Hypersonic Laboratory Experimentsmentioning

confidence: 85%

Section: A Analyses Of Hypersonic Laboratory Experimentsmentioning

confidence: 99%

See 1 more Smart Citation

Computation of Hypersonic Flows Using the Direct Simulation Monte Carlo Method

Boyd

2015

Journal of Spacecraft and Rockets

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“…In the current study, an existing DSMC code is used that has been extensively verified and validated [4][5][6]. The No Time Counter technique [2] and the Variable Hard Sphere (VHS) model [2] are used to simulate collisions between particles.…”

Section: Methodsmentioning

confidence: 99%

Subsonic flow boundary conditions for the direct simulation Monte Carlo method

Farbar

Boyd

2014

Computers & Fluids

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“…A variety of very small models were tested that included cones as well as capsules such as Apollo, Gemini, and Mercury. The MONACO DSMC code was applied to simulate the tests on the cones that were conducted in a Mach 10 flow of nitrogen at a global Knudsen number of 0.065 [62]. Figure 14a shows contours of Mach number computed for an angle of attack of 20 deg.. Figures 14b and 14c show comparisons for aerodynamic properties between measurement and simulation.…”

Section: Dsmc Analyses Of Hypersonic Laboratory Experimentsmentioning

confidence: 99%

Computation of Hypersonic Flows Using the Direct Simulation Monte Carlo Method

Boyd

2013

21st AIAA Computational Fluid Dynamics Conference

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The direct simulation Monte Carlo method (DSMC) has evolved over 50 years into a powerful numerical technique for the computation of complex, nonequilibrium gas flows. In this context, nonequilibrium means that the velocity distribution function is not in an equilibrium form due to a low number of intermolecular collisions within a fluid element. In hypersonic flow, nonequilibrium conditions occur at high altitude and in regions of flow fields with small length scales. In this article, the theoretical basis of the DSMC technique is discussed. In addition, the methods used in DSMC are described for simulation of high temperature, real gas effects and gas-surface interactions. Several examples of the application of DSMC to flows around blunt hypersonic vehicles are presented to illustrate current capabilities.

show abstract

Assessment of Rarefied Hypersonic Aerodynamics Modeling and Windtunnel Data

Cited by 17 publications

References 12 publications

Computation of Hypersonic Flows Using the Direct Simulation Monte Carlo Method

Computation of Hypersonic Flows Using the Direct Simulation Monte Carlo Method

Subsonic flow boundary conditions for the direct simulation Monte Carlo method

Computation of Hypersonic Flows Using the Direct Simulation Monte Carlo Method

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