墙壁温度对稀释气体流量和微喷嘴中的热传递的影响
Shurui Zhang1, Yong Li2, Xudong Wang2
1Hydrogen Energy and Space Propulsion Laboratory (HESPL), School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China.
Micromachines
|January 23, 2024
概括
卫星推进器壁的温度会影响稀释气体的流量. 本研究使用直接模拟蒙特卡洛 (DSMC) 方法分析了微喷嘴温度对流量和热传输的影响.
科学领域:
- 航空航天工程 航空航天工程
- 流体动力学 流体动力学
- 热力学是一种热力学.
背景情况:
- 由于太阳辐射,卫星冷气微推进器面临极端的温度变化 (100-1000 K).
- 这些温度变化显著影响微喷嘴结构内的稀释气体流量.
研究的目的:
- 研究不同墙壁温度对稀释气体流动和微喷嘴中的热传输的影响.
- 分析温度影响的多尺度流量特征,在具有高长度对直径比率和小门位移的微通道中.
主要方法:
- 采用直接模拟蒙特卡罗 (DSMC) 方法来模拟稀释气体流.
- 在微型喷嘴上计算了局部克努森数,滑动速度,温度和墙壁热流的分布.
主要成果:
- 识别的滑动流区域以大约50m/s的滑动速度转化为过渡流.
- 观察到墙壁温度在小针门口的流动模式中占主导地位.
- 较高的墙壁温度与微型喷嘴内温度下降的减少有关.
结论:
- 墙壁温度是影响微喷嘴中稀释气体动态的一个关键参数.
- 结果为设计卫星微推进器的有效温度控制系统提供了宝贵的见解.
相关概念视频
Poiseuille's Law and Reynolds Number
6.6K
Any fluid in a horizontal tube can flow due to pressure differences—fluid flows from high to low pressure. The flow rate (Q) is the ratio of pressure difference and resistance through a horizontal tube. The greater the pressure difference, the higher the flow rate. The flow resistance is expressed as:
6.6K
Laminar Flow: Problem Solving
181
Laminar flow occurs when a fluid moves smoothly in parallel layers with minimal mixing and turbulence. In fluid mechanics, ensuring laminar flow within a pipe is essential for precise control of flow characteristics, especially in engineering applications. The key factor in determining whether flow remains laminar is the Reynolds number, a dimensionless quantity that depends on the fluid's velocity, density, viscosity, and the pipe's diameter. A Reynolds number of 2100 or lower...
181
Steady, Laminar Flow in Circular Tubes
210
Hagen-Poiseuille flow describes a viscous fluid's steady, incompressible flow through a cylindrical tube with a constant radius R. This flow profile is often applied to understand fluid transport in narrow channels, such as capillaries. It serves as a foundational example of laminar flow. In this model, cylindrical coordinates (r,θ,z) are used to describe the radial (r), angular (θ), and axial (z) dimensions within the tube. For Hagen-Poiseuille flow, the velocity profile is...
210
Free Jet
165
Free jets describe the flow of liquid exiting a reservoir through an opening into the atmosphere without resistance. The velocity (v) of the liquid jet is derived using Bernoulli's principle and expressed as:
165
Turbulent Flow: Problem Solving
130
Carbonation is a process used to dissolve carbon dioxide gas in a liquid, commonly used in the production of carbonated beverages. Achieving efficient carbonation requires careful control of temperature, pressure, and flow conditions. By adjusting these parameters, carbonation efficiency can be maximized, producing a higher concentration of CO2 in the liquid.
Temperature is a key factor in CO2 solubility. In this case, the CO2 gas and the liquid are cooled to 20°C. Lower temperatures...
Temperature is a key factor in CO2 solubility. In this case, the CO2 gas and the liquid are cooled to 20°C. Lower temperatures...
130
Laminar Flow
1.1K
Laminar flow represents a smooth, orderly fluid motion where particles move along parallel paths, resulting in minimal mixing between layers. Streamlined particle paths characterize this flow regime and occur under conditions where viscous forces dominate over inertial forces. The distinction between laminar, transitional, and turbulent flow is primarily determined by the Reynolds number, a dimensionless quantity calculated as:
1.1K


