博士 / 國立交通大學 / 機械工程系所 / 103 / The aim of this thesis is to investigate gases discharged from a high pressure vessel numerically. To simulate this subject more realistically, the viscosity and compressibility of the gas are taken into consideration simultaneously. The methods of the Roe scheme, preconditioning and dual time stepping matching the LUSGS method are adopted to solve compressible flow problems during gaseous discharge processes. The non-reflecting boundary condition is used to prevent flow fields from being polluted by the reflection of the pressure wave induced by the compressible flow on the boundary. Computing procedures are performed on the Compute Unified Device Architecture (CUDA) computation platform which was recently developed and a highly effective technology for accelerating computational speed. The pressure ratio, which means the ratio of the pressure in the vessel to the pressure of outside, is larger than 1.89. Thus both subsonic and supersonic speeds of the discharged gas are investigated. Results show that the mass flow rate of this work is consistent with the existing experimental work. Due to a sudden expansion at a small opening, the phenomena of an alternating variation of the pressures of gases, rapid decrements of the temperature of gases and a quick acceleration of the velocities of gases are clearly observed in the mainstream direction. The ratio of the thrust caused by the gases released to the reaction force is less than 1 because of the dissipation of entropy generation. Also, a modified equation for predicting transient mass flow rates is derived. Results obtained by the equation have good agreements with results that calculated by the numerical method developed bt this work.
| Identifer | oai:union.ndltd.org:TW/103NCTU5489095 |
| Date | January 2015 |
| Creators | Huang, Kun-Rong, 黃崑榕 |
| Contributors | Fu, Wu-Shung, 傅武雄 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 189 |
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