• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>PID-vol.9; ASME International Mechanical Engineering Congress and Exposition; 20041113-19; Anaheim,CA(US) >A MICRO STATE DYNAMIC MODEL COMPATIBILITY CONDITIONS FOR THE ONE DIMENSIONAL NON-STATIONARY COMPRESSIBLE FLOW IN PRESSURE WAVE MACHINES
【24h】

A MICRO STATE DYNAMIC MODEL COMPATIBILITY CONDITIONS FOR THE ONE DIMENSIONAL NON-STATIONARY COMPRESSIBLE FLOW IN PRESSURE WAVE MACHINES

机译：压力波机中一维非平稳可压缩流的微状态动力学模型和相容性条件

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Shock tube like applications such as the pressure wave machines are subjected to the possible build up of moving discontinuities in the material, temperature and pressure .The method of characteristics offered a suitable platform to take these aspects into consideration. Jenny has applied this method to obtain the direction and the corresponding compatibility conditions for the isentropic non-stationary one dimensional gas flow. Following Jenny's derivation, it was possible to derive the general compatibility conditions along the corresponding characteristic directions. The variable grid method used a second order approximation of the direction and compatibility conditions. A system of non-linear equations for the local states and the grid positions was obtained. In spite of the accurate results achieved by the variable grid method, the obligation to grid reorganization -while numerically tractable- have drawn the attention to the possibility that there may be persistent and inherent analytical/physical inadequacy with respect to the resulting compatibility equations that are numerically reflected by inhomogeneous build up of the variable grid. This paper, therefore, revisits the formulation of the dynamics of the one dimensional non stationary compressible flow and develops a new micro state dynamic model. The micro state equations of continuity, momentum and energy are derived. A micro state variable such as Θ or P represents the micro state dynamics, while the corresponding flow variables of temperature Τ or density ρ are to be regarded as observed measurement variables. Further, the micro state compatibility conditions are derived . The resulting micro state total differentials dS_0 & dS_± along the particle path & sound propagation ± Lines are linear functions of the micro state differentials. It is shown that dS_0 is the total differential of the micro state energy equation along the particle path. It is proportional to the "Clausius" -entropy differential ds through the gas constant R and to the differential of the number of micro states dΩ~* in "Boltzmann"-relation by the Avogadro number N_A. For isentropic flow , dS_± is proportional -through κ and the sound speed a - to the transformed micro state "Riemann "-differential dR_±. Otherwise, the relation ±Δ_a~bR_±= [Δ_a~bS_±+Δ_a~bS_0] holds along the ± Lines where ±Δ_a~bR_± & Δ_a~bS_± are the weighted change of the micro state differential of Riemann-Invariants and the change of dS_± along the ± Lines respectively. Δ_a~bS_0 is the "jump" along the ± Lines of dS_0. Beside providing novel micro state compatibility conditions for the variable grid method, the presented formulation clears the existence as well as the sign of entropy change (reversibility/irreversibility) within the second law of thermodynamics.
机译：像冲击波之类的冲击波应用（例如压力波机）可能会在材料，温度和压力中移动不连续，因此特性方法提供了一个合适的平台来考虑这些方面。 Jenny已应用此方法来获得等熵非平稳一维气流的方向和相应的相容性条件。在詹妮（Jenny）的推导之后，就有可能沿着相应的特征方向推导一般的相容性条件。可变网格方法使用方向和兼容性条件的二阶近似。获得了局部状态和网格位置的非线性方程组。尽管通过可变网格方法获得了准确的结果，但网格重组的义务（尽管在数值上易于处理）吸引了人们注意以下可能性，即对于由此产生的兼容性方程，可能存在持久的和固有的分析/物理不足之处可变网格的不均匀累积在数值上反映出来。因此，本文重新审视了一维非平稳可压缩流动的动力学公式，并开发了一种新的微状态动力学模型。导出了连续性，动量和能量的微状态方程。微观状态变量（例如Θ或P）表示微观状态动态，而温度Τ或密度ρ的相应流量变量应视为观察到的测量变量。此外，推导了微状态相容性条件。沿着粒子路径和声音传播±产生的微状态总微分dS_0和dS_±线是微状态微分的线性函数。结果表明，dS_0是沿粒子路径的微态能量方程的总微分。它与通过气体常数R的“克劳修斯”熵微分ds成正比，并且与“玻尔兹曼”关系中的微状态数dΩ〜*的微分成Avogadro数N_A。对于等熵流，dS_±与κ成比例，并且声速a与转化后的微状态“ Riemann”-微分dR_±成正比。否则，关系±Δ_a〜bR_±= [Δ_a〜bS_±+Δ_a〜bS_0]沿±线成立，其中±Δ_a〜bR_±和Δ_a〜bS_±是黎曼不变量的微状态微分的加权变化和dS_±分别沿±线的变化。 Δ_a〜bS_0是沿dS_0的±线的“跳跃”。除了为可变网格方法提供新颖的微状态相容性条件外，本文提出的公式还清除了热力学第二定律中熵变化（可逆性/不可逆性）的存在和征兆。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号