TY - JOUR
T1 - Atomistic simulation of micro-scale adiabatic piston problem
AU - Sengil, Nevsan
AU - Oguz Edis, Firat
PY - 2009/10/16
Y1 - 2009/10/16
N2 - Purpose- The purpose of this paper is to demonstrate the utilization of the direct simulation Monte Carlo (DSMC) method for moving-boundary/deforming-domain micro-scale gas flow problems. Furthermore, a hydrodynamic model, proposed in the literature, is used to compare its results with those obtained using the DSMC method.Design/methodology/approach- A micro-scale adiabatic piston problem is analyzed using a parallel DSMC implementation for deforming domains. Initially, pressures at both sides of the piston wall are different. Consequently, frictionless piston moves toward low-pressure compartment, keeps oscillating from one side to the other. Eventually, the piston reaches the “Mechanical equilibrium” state. Although the temperatures are different, pressures are equal at this state. The unsteady problem is analyzed until it reaches this state. Three test cases, all with the same initial conditions but different piston masses are analyzed. The time variation of the piston position, conditions in the compartments separated by the piston, are presented and compared with the results obtained from a hydrodynamic model proposed in the literature.Findings- The results show that the DSMC and hydrodynamic results agree for the case where the piston mass is much larger than the mass of the gas inside the cylinder. But for other two cases, where the piston mass is smaller, piston motion, and conditions in the compartments separated by the piston differ for the two methods. This is attributed to the linear velocity distribution assumption of the hydrodynamic model. The DSMC results demonstrate that this assumption is not valid for cases where the piston mass is equal or less than the mass of the gas inside the cylinder.Originality/value- Implementation of the DSMC method for problems with deforming domain is presented and a limitation for applicability of hydrodynamic model for these problems is shown.
AB - Purpose- The purpose of this paper is to demonstrate the utilization of the direct simulation Monte Carlo (DSMC) method for moving-boundary/deforming-domain micro-scale gas flow problems. Furthermore, a hydrodynamic model, proposed in the literature, is used to compare its results with those obtained using the DSMC method.Design/methodology/approach- A micro-scale adiabatic piston problem is analyzed using a parallel DSMC implementation for deforming domains. Initially, pressures at both sides of the piston wall are different. Consequently, frictionless piston moves toward low-pressure compartment, keeps oscillating from one side to the other. Eventually, the piston reaches the “Mechanical equilibrium” state. Although the temperatures are different, pressures are equal at this state. The unsteady problem is analyzed until it reaches this state. Three test cases, all with the same initial conditions but different piston masses are analyzed. The time variation of the piston position, conditions in the compartments separated by the piston, are presented and compared with the results obtained from a hydrodynamic model proposed in the literature.Findings- The results show that the DSMC and hydrodynamic results agree for the case where the piston mass is much larger than the mass of the gas inside the cylinder. But for other two cases, where the piston mass is smaller, piston motion, and conditions in the compartments separated by the piston differ for the two methods. This is attributed to the linear velocity distribution assumption of the hydrodynamic model. The DSMC results demonstrate that this assumption is not valid for cases where the piston mass is equal or less than the mass of the gas inside the cylinder.Originality/value- Implementation of the DSMC method for problems with deforming domain is presented and a limitation for applicability of hydrodynamic model for these problems is shown.
KW - Deformation
KW - Fluidics
KW - Gas flow
KW - Monte Carlo methods
UR - http://www.scopus.com/inward/record.url?scp=73849097905&partnerID=8YFLogxK
U2 - 10.1108/00022660910997793
DO - 10.1108/00022660910997793
M3 - Article
AN - SCOPUS:73849097905
SN - 0002-2667
VL - 81
SP - 499
EP - 507
JO - Aircraft Engineering and Aerospace Technology
JF - Aircraft Engineering and Aerospace Technology
IS - 6
ER -