Numerical simulations on performance of MEMS-based nozzles at moderate or low temperatures

Performance of microelectromechanical systems (MEMS)-based nozzles at moderate and low temperatures is numerically analyzed using the direct simulation Monte Carlo method. Considering the intermolecular attractive potential caused by low temperature, the generalized soft sphere collision model is introduced. The Larsen–Borgnakke model for the generalized sphere model is used to model the energy exchange between the translational and internal modes. The results for nozzle flows at an initial temperature of 300 K show that the temperature behind the throat is quite low and the intermolecular attractive potential cannot be ignored. Different working conditions in two-dimensional (2D) nozzles are simulated using the present method, including exit pressure, inlet pressure, initial temperature, nozzle geometry, and gas species. The effects on the nozzle performance are analyzed. Simulations on flows in a three-dimensional (3D) low aspect ratio flat nozzle show that the increased surface-to-volume ratio, which leads to high viscosity dissipation, causes a much lower flow characteristic and performance comparing with the 2D case.

[1]  Kenneth S. Breuer,et al.  Viscous Effects in Supersonic MEMS-Fabricated Micronozzles , 1998, Micro-Electro-Mechanical Systems (MEMS).

[2]  J. S. Marshall,et al.  Molecular Theory of Gases , 1967 .

[3]  Mikhail S. Ivanov,et al.  Statistical simulation of reactive rarefied flows - Numerical approach and applications , 1998 .

[4]  Alina Alexeenko,et al.  Numerical simulation of high-temperature gas flows in a Millimeter-Scale thruster , 2001 .

[5]  Hassan Hassan,et al.  A generalized hard‐sphere model for Monte Carlo simulation , 1993 .

[6]  Numerical Simulation of Rarefied Plume Flow Exhausting from a Small Nozzle , 2003 .

[7]  The GHS interaction model for strong attractive potentials , 1995 .

[8]  Robert Louis Bayt,et al.  Analysis, Fabrication and Testing of a MEMS-based Micropropulsion System , 1999 .

[9]  Henrik Kratz,et al.  A Hybrid Cold Gas Microthruster System for Spacecraft , 2002 .

[11]  William W. Liou,et al.  Computations of the Flow and Heat Transfer in Microdevices Using DSMC With Implicit Boundary Conditions , 2002 .

[12]  R. B. Cohen,et al.  Digital MicroPropulsion , 1999, Technical Digest. IEEE International MEMS 99 Conference. Twelfth IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.99CH36291).

[13]  Wang Mo.  THREE-DIMENSIONAL EFFECT OF GAS FLOW IN MICRO CHANNELS , 2004 .

[14]  Gerald Hagemann,et al.  Advanced Rocket Nozzles. , 1998 .

[15]  Mikhail S. Ivanov,et al.  Numerical study of 2D/3D micronozzle flows , 2002 .

[16]  I. Kuščer.  A model for rotational energy exchange in polyatomic gases , 1989 .

[17]  Jing Fan,et al.  A generalized soft-sphere model for Monte Carlo simulation , 2002 .

[18]  G. Bird.  Molecular Gas Dynamics and the Direct Simulation of Gas Flows , 1994 .

[19]  C. Kerechanin,et al.  Effects of Nozzle Trailing Edges on Acoustic Field of Supersonic Rectangular Jet , 2001 .

[20]  Iain D. Boyd.  Temperature dependence of rotational relaxation in shock waves of nitrogen , 1993 .

[21]  Alina A. Alexeenko,et al.  Numerical Investigation of Physical Processes in High‐Temperature MEMS‐based Nozzle Flows , 2003 .

[22]  David B. Hash,et al.  Direct simulation of diatomic gases using the generalized hard sphere model , 1994 .