scholarly journals Kinetic comparative study on Aerodynamic Characteristics of Hypersonic Reentry Vehicle from Near-continuous Flow to Free Molecular Flow

2021 ◽  
Author(s):  
Jin Li ◽  
Dingwu Jiang ◽  
Xiangren Geng ◽  
Jianqiang Chen
Keyword(s):  
Direct Simulation Monte Carlo ◽  
Kinetic Scheme ◽  
Aerodynamic Characteristics ◽  
Molecular Flow ◽  
Direct Simulation ◽  
Scaled Model ◽  
Reentry Vehicle ◽  
Simulation Monte Carlo ◽  
Unified Gas Kinetic Scheme ◽  
Inflow Conditions

Abstract A scaled model of the X38-like configuration was simulated under hypersonic conditions by the direct simulation Monte Carlo method and the unified gas kinetic scheme. The inflow conditions considered several different flow regimes, from the near-continuum though the slip-transitional to the free molecule regime. Flow fields and surface properties were compared in details between two methods. Not only the density and temperature contours distribution but also the surface pressure, heat flux, friction distribution, both kinetic methods give fairly consistent results. Aerodynamics of the model under hypersonic rarefied conditions were also obtained and compared. The results given by both methods agreed with each other very well. The effects of the Knudsen number and angle of attack were assessed. At the absence of experimental results, it is meaningful to carry out comparative studies and accelerate both methods to further progress.

scholarly journals Kinetic comparative study on aerodynamic characteristics of hypersonic reentry vehicle from near-continuous flow to free molecular flow

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Jin Li ◽  
Dingwu Jiang ◽  
Xiangren Geng ◽  
Jianqiang Chen
Keyword(s):  
Direct Simulation Monte Carlo ◽  
Kinetic Scheme ◽  
Aerodynamic Characteristics ◽  
Molecular Flow ◽  
Direct Simulation ◽  
Scaled Model ◽  
Reentry Vehicle ◽  
Simulation Monte Carlo ◽  
Unified Gas Kinetic Scheme ◽  
Inflow Conditions

AbstractA scaled model of the X38-like configuration was simulated under hypersonic conditions for the direct simulation Monte Carlo method and the unified gas kinetic scheme. The inflow conditions considered several flow regimes, from the near-continuum through the slip-transitional to the free molecular regime. Flow fields and surface properties were compared in detail between these two methods. Not only the density and temperature contours distribution but also the surface pressure, heat flux, friction distribution, both kinetic methods give fairly consistent results. Aerodynamics of the model were also achieved and compared. The results provided by both methods agreed with each other very well. The effects of the Knudsen number and angle of attack were assessed. It is meaningful to carry out comparative studies and accelerate both methods to further progress.

scholarly journals Kinetic Comparative Study on Aerodynamic Characteristics of Hypersonic Reentry Vehicle from Near-Continuous Flow to Free Molecular Flow

2020 ◽  
Author(s):  
Jin Li ◽  
Dingwu Jiang ◽  
Xiangren Geng ◽  
Jianqiang Chen
Keyword(s):  
Continuous Flow ◽  
Direct Simulation Monte Carlo ◽  
Kinetic Scheme ◽  
Free Molecule ◽  
Direct Simulation ◽  
Scaled Model ◽  
Reentry Vehicle ◽  
Simulation Monte Carlo ◽  
Unified Gas Kinetic Scheme ◽  
Inflow Conditions

Abstract A scaled model of the X38-like configuration was simulated under hypersonic conditions by the direct simulation Monte Carlo method and the unified gas kinetic scheme. The inflow conditions considered several different flow regimes, from the near-continuum though the slip-transitional to the free molecule regime. Flow fields and surface properties were compared in details between two methods. Not only the density and temperature contours distribution but also the surface pressure, heat flux, friction distribution, both kinetic methods give fairly consistent results. Aerodynamics of the model under hypersonic rarefied conditions were also obtained and compared. The results given by both methods agreed with each other very well. The effects of the Knudsen number and angle of attack were assessed. At the absence of experimental results, it is meaningful to carry out comparative studies and accelerate both methods to further progress.

Unified Gas Kinetic Scheme and Direct Simulation Monte Carlo Computations of High-Speed Lid-Driven Microcavity Flows

2015 ◽  
Vol 17 (5) ◽  
pp. 1127-1150 ◽  
Author(s):  
Vishnu Venugopal ◽  
Sharath S. Girimaji
Keyword(s):  
Monte Carlo ◽  
High Speed ◽  
Direct Simulation Monte Carlo ◽  
Kinetic Scheme ◽  
Cavity Flow ◽  
Direct Simulation ◽  
Driven Cavity ◽  
Rarefied Flows ◽  
Simulation Monte Carlo ◽  
Unified Gas Kinetic Scheme

AbstractAccurate simulations of high-speed rarefied flows present many physical and computational challenges. Toward this end, the present work extends the Unified Gas Kinetic Scheme (UGKS) to a wider range of Mach and Knudsen numbers by implementing WENO (Weighted Essentially Non-Oscillatory) interpolation. Then the UGKS is employed to simulate the canonical problem of lid-driven cavity flow at high speeds. Direct Simulation Monte Carlo (DSMC) computations are also performed when appropriate for comparison. The effect of aspect ratio, Knudsen number and Mach number on cavity flow physics is examined leading to important insight.

Improved estimation of aerodynamic characteristics of a complex geometry nanosatellite

2021 ◽  
Author(s):  
E.V. Barinova ◽  
E.A. Boltov ◽  
N.A. Elisov ◽  
I.A. Lomaka
Keyword(s):  
Finite Element ◽  
Monte Carlo ◽  
Drag Coefficient ◽  
Complex Geometry ◽  
Direct Simulation Monte Carlo ◽  
Aerodynamic Characteristics ◽  
Thermal Velocity ◽  
Direct Simulation ◽  
Simulation Monte Carlo ◽  
Aerodynamic Torque

The paper presents an approach to refine the aerodynamic characteristics (drag coefficient, aerodynamic torque) of a complex-geometry nanosatellite. The approach is based on the direct simulation Monte-Carlo method. The calculations took into account gas−surface interaction according to Cercignani—Lampis—Lord model, chemical composition of atmosphere on the orbit altitude and particle thermal velocity. The nanosatellite complex geometry was described as a finite-element grid with the cell size of 5 mm. The results of the engineering and numerical methods were compared. The differences in drag coefficient and aerodynamic torque between the two methods reached 20%.

Numerical Methods for the Kinetic Theory of Fluids

2018 ◽  
Author(s):  
Sauro Succi
Keyword(s):  
Molecular Dynamics ◽  
Monte Carlo ◽  
Numerical Methods ◽  
Kinetic Theory ◽  
Computational Efficiency ◽  
Lattice Boltzmann ◽  
Direct Simulation Monte Carlo ◽  
Particle Methods ◽  
Direct Simulation ◽  
Simulation Monte Carlo

This chapter provides a bird’s eye view of the main numerical particle methods used in the kinetic theory of fluids, the main purpose being of locating Lattice Boltzmann in the broader context of computational kinetic theory. The leading numerical methods for dense and rarified fluids are Molecular Dynamics (MD) and Direct Simulation Monte Carlo (DSMC), respectively. These methods date of the mid 50s and 60s, respectively, and, ever since, they have undergone a series of impressive developments and refinements which have turned them in major tools of investigation, discovery and design. However, they are both very demanding on computational grounds, which motivates a ceaseless demand for new and improved variants aimed at enhancing their computational efficiency without losing physical fidelity and vice versa, enhance their physical fidelity without compromising computational viability.

Study on the Deposition Profile Characteristics in the Micron-Scale Trench Using Direct Simulation Monte Carlo Method

1998 ◽  
Vol 120 (2) ◽  
pp. 296-302 ◽  
Author(s):  
Masato Ikegawa ◽  
Jun’ichi Kobayashi ◽  
Morihisa Maruko
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Boundary Conditions ◽  
Gas Flow ◽  
Direct Simulation Monte Carlo ◽  
Low Pressure ◽  
Sputter Deposition ◽  
Direct Simulation ◽  
Simulation Monte Carlo ◽  
Profile Characteristics

As integrated circuits are advancing toward smaller device features, step-coverage in submicron trenches and holes in thin film deposition are becoming of concern. Deposition consists of gas flow in the vapor phase and film growth in the solid phase. A deposition profile simulator using the direct simulation Monte Carlo method has been developed to investigate deposition profile characteristics on small trenches which have nearly the same dimension as the mean free path of molecules. This simulator can be applied to several deposition processes such as sputter deposition, and atmospheric- or low-pressure chemical vapor deposition. In the case of low-pressure processes such as sputter deposition, upstream boundary conditions of the trenches can be calculated by means of rarefied gas flow analysis in the reactor. The effects of upstream boundary conditions, molecular collisions, sticking coefficients, and surface migration on deposition profiles in the trenches were clarified.

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