Rarefied Nozzle Flow Computation Using the Viscosity-Based Direct Simulation Monte Carlo Method
Micro-nozzles are essential for enabling precise satellite attitude control and orbital maneuvers. Accurate prediction of performance parameters, including thrust and specific impulse, is critical, necessitating careful design of these nozzles. Given the high Knudsen numbers associated with micro-no...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-12-01
|
| Series: | Fluids |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2311-5521/10/1/2 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832588461825064960 |
|---|---|
| author | Deepa Raj Mopuru Nishanth Dongari Srihari Payyavula |
| author_facet | Deepa Raj Mopuru Nishanth Dongari Srihari Payyavula |
| author_sort | Deepa Raj Mopuru |
| collection | DOAJ |
| description | Micro-nozzles are essential for enabling precise satellite attitude control and orbital maneuvers. Accurate prediction of performance parameters, including thrust and specific impulse, is critical, necessitating careful design of these nozzles. Given the high Knudsen numbers associated with micro-nozzle flows, rarefied gas dynamics often dominate, and conventional computational fluid dynamics (CFD) methods fail to capture accurate flow expansion behavior. The Direct Simulation Monte Carlo (DSMC) method, developed by Bird, is widely used for modeling rarefied flows; however, it has been primarily implemented on platforms like OpenFOAM and FORTRAN, with limited exploration in MATLAB. This study presents the development of a viscosity-based DSMC (μDSMC) simulation framework in MATLAB for analyzing rarefied gas expansion through micro-nozzles. Key boundary conditions, including upstream and downstream pressure conditions and thermal wall treatments with diffuse reflection, are incorporated into the code. The μDSMC results are validated against traditional DSMC outcomes, showing strong agreement. Grid convergence studies indicate that the radial grid size must be less than one-third of the mean free path, with a more relaxed requirement on axial grid size. Flow characteristics within micro-nozzles are evaluated across varying ambient pressures and gas species in terms of the back pressure ratio, effective exit flow ratio, and exit flow velocity. Studies indicated that a minimum back pressure ratio is required, beyond which the effective nozzle flow expansion is achieved. Parametric analysis further suggests that gases with lower molecular weights are preferable for achieving optimal expansion in micro-nozzles under low ambient pressures. |
| format | Article |
| id | doaj-art-0b79cc673c9e49c6a50a3e3dfa2bea19 |
| institution | Kabale University |
| issn | 2311-5521 |
| language | English |
| publishDate | 2024-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fluids |
| spelling | doaj-art-0b79cc673c9e49c6a50a3e3dfa2bea192025-01-24T13:32:32ZengMDPI AGFluids2311-55212024-12-01101210.3390/fluids10010002Rarefied Nozzle Flow Computation Using the Viscosity-Based Direct Simulation Monte Carlo MethodDeepa Raj Mopuru0Nishanth Dongari1Srihari Payyavula2Defence Research & Development Laboratory, Kanchanbagh, Hyderabad 500058, IndiaDepartment of Mechanaical & Aerospace Engineering, Indian Institute of Technology, Hyderabad, Sangareddy 502285, IndiaResearch Centre Imarat, Vigyanakancha, Hyderabad 500069, IndiaMicro-nozzles are essential for enabling precise satellite attitude control and orbital maneuvers. Accurate prediction of performance parameters, including thrust and specific impulse, is critical, necessitating careful design of these nozzles. Given the high Knudsen numbers associated with micro-nozzle flows, rarefied gas dynamics often dominate, and conventional computational fluid dynamics (CFD) methods fail to capture accurate flow expansion behavior. The Direct Simulation Monte Carlo (DSMC) method, developed by Bird, is widely used for modeling rarefied flows; however, it has been primarily implemented on platforms like OpenFOAM and FORTRAN, with limited exploration in MATLAB. This study presents the development of a viscosity-based DSMC (μDSMC) simulation framework in MATLAB for analyzing rarefied gas expansion through micro-nozzles. Key boundary conditions, including upstream and downstream pressure conditions and thermal wall treatments with diffuse reflection, are incorporated into the code. The μDSMC results are validated against traditional DSMC outcomes, showing strong agreement. Grid convergence studies indicate that the radial grid size must be less than one-third of the mean free path, with a more relaxed requirement on axial grid size. Flow characteristics within micro-nozzles are evaluated across varying ambient pressures and gas species in terms of the back pressure ratio, effective exit flow ratio, and exit flow velocity. Studies indicated that a minimum back pressure ratio is required, beyond which the effective nozzle flow expansion is achieved. Parametric analysis further suggests that gases with lower molecular weights are preferable for achieving optimal expansion in micro-nozzles under low ambient pressures.https://www.mdpi.com/2311-5521/10/1/2rarefied flow expansionmicro-nozzleDSMCMATLABvariable hard sphereattitude control |
| spellingShingle | Deepa Raj Mopuru Nishanth Dongari Srihari Payyavula Rarefied Nozzle Flow Computation Using the Viscosity-Based Direct Simulation Monte Carlo Method Fluids rarefied flow expansion micro-nozzle DSMC MATLAB variable hard sphere attitude control |
| title | Rarefied Nozzle Flow Computation Using the Viscosity-Based Direct Simulation Monte Carlo Method |
| title_full | Rarefied Nozzle Flow Computation Using the Viscosity-Based Direct Simulation Monte Carlo Method |
| title_fullStr | Rarefied Nozzle Flow Computation Using the Viscosity-Based Direct Simulation Monte Carlo Method |
| title_full_unstemmed | Rarefied Nozzle Flow Computation Using the Viscosity-Based Direct Simulation Monte Carlo Method |
| title_short | Rarefied Nozzle Flow Computation Using the Viscosity-Based Direct Simulation Monte Carlo Method |
| title_sort | rarefied nozzle flow computation using the viscosity based direct simulation monte carlo method |
| topic | rarefied flow expansion micro-nozzle DSMC MATLAB variable hard sphere attitude control |
| url | https://www.mdpi.com/2311-5521/10/1/2 |
| work_keys_str_mv | AT deeparajmopuru rarefiednozzleflowcomputationusingtheviscositybaseddirectsimulationmontecarlomethod AT nishanthdongari rarefiednozzleflowcomputationusingtheviscositybaseddirectsimulationmontecarlomethod AT sriharipayyavula rarefiednozzleflowcomputationusingtheviscositybaseddirectsimulationmontecarlomethod |