Plume impingement investigation using Monte-Carlo computations

Abstract

Numerical simulations have been performed to explore the effects of important design parameters on impingement disturbance properties of multiple hydrazine thruster plumes. The particle behaviour of the far-field plume flows near the impingement surfaces is modelled using the collisionless molecular direct simulation Monte-Carlo method with the inflow boundary condition derived from the velocity and temperature profiles at the nozzle exit. The entering molecular motions and the impact interactions between molecules and solid boundaries are treated on a probabilistic basis, whereas the main flow properties are preserved from the transformation of the microscopic fluid activities of simulated molecules. To validate the present computer code, the predicted transverse Pitot pressure profile was compared with the measured data in the far plume region of an MBB/ERNO 0.5-N conical nozzle. On the basis of the ROCSAT-1 design configuration, the calculated plume disturbance torques are examined in the yaw, roll, and pitch directions for different settings of the canted angle of the thruster mounting and the satellite centre-of-mass (CM) offset. Predictions show that the normalized yaw impingement disturbance torque reaches 6.3 per cent at the cant angle of 30°, indicating that the associated plume collision effect on the attitude control can be important at large cant angles. In addition, the location change of the satellite CM in the axial axis reveals insignificant influence on the impingement torque for the offset value varying from −5.0 to 5.0 cm.

DSMC simulation of rarefied gas flow over a 2D backward-facing step in the transitional flow regime: Effect of Mach number and wall temperature

“…42 The main benefit of the DSMC is its numerical stability, and it does not depend on similarity parameters like the Mach number, Reynolds number,, 43 furthermore, with the development of supercomputers, 44 DSMC technique in the latest years, has become a diverse and successful one. 45 Though DSMC is the right approach for modeling microscale flows, 46–48 at low speeds, the statistical noise is significant and limits the accuracy of results. Also, it has drawbacks such as slow convergence and requirement of a large number of simulated molecules; a thorough description is given in literature.…”

Combined Analysis of Thruster Plume Behavior in Rarefied Region by Preconditioned Navier-Stokes and DSMC Methods

“…[3][4][5] Chung et al 3) used the N-S method to compute the flow in the subsonic region of a low density nozzle and the DSMC code was taken for its supersonic portion, respectively. Ó 2009 The Japan Society for Aeronautical and Space Sciences Vashchenkov et al 4) studied the plume backflow phenomenon for various shapes of a supersonic nozzle with a low Reynolds number and concluded that use of the combined N-S/DSMC approach is essentially important to simulate flow in a rarefied environment.…”

“…Ó 2009 The Japan Society for Aeronautical and Space Sciences Vashchenkov et al 4) studied the plume backflow phenomenon for various shapes of a supersonic nozzle with a low Reynolds number and concluded that use of the combined N-S/DSMC approach is essentially important to simulate flow in a rarefied environment. In addition, Yang 5) investigated the effect of thruster plume impingement on the satellite using the collisionless DSMC method for simplicity in conjunction with N-S method. Here, the internal flow in a nozzle is assumed to be laminar, and the turbulence effect is ignored.…”