典型流阻元件的流量和熵产模型研究

Flow Rate and Entropy Generation Model of Typical Flow Resistance Elements

关键词:  质量流量模型  熵产模型  预旋喷嘴  篦齿封严  流量系数

Key words:  Mass flow rate model  Entropy generation model  Pre-swirl nozzle  Labyrinth seal  Discharge coefficient

摘要:

为揭示流阻元件的流动损失机理，从热力学理论出发，建立了流阻元件的质量流量模型和熵产模型，分析了质量流量与熵产之间的关系，研究了熵产随系统压比和进口总压的变化情况，并通过预旋喷嘴和篦齿封严的实验结果对两个模型进行了分析评估。结果表明，质量流量模型与实验结果的最大偏差不超过2.8%；熵产模型与实验结果的最大偏差不超过1.9%。系统熵产随系统压比的增加而增大，随进口总压的增加而减小。当系统的进口总压、进口总温和出口静压不变时，模型中的参数a是衡量不同元件熵产大小的唯一量度。

Abstract:

To reveal the flow loss mechanism of flow resistance elements， a flow rate model and an entropy generation model based on thermodynamic theories for a resistance element were established， and the relationship between the mass flow rate and the entropy generation was analyzed. The variation of entropy generation with system pressure ratio and inlet total pressure was researched. The errors of two models were given by the experimental results of the pre-swirl nozzle and the labyrinth seal. It is found that the maximum deviation between the mass flow rate model and the experimental results is less than 2.8%. The maximum deviation between the entropy generation model and the experimental results is less than 1.9%. The system entropy generation increased with the increase of system pressure ratio， but decreased with the increase of inlet total pressure. The parameter a in the model is the only indictor to measure the size of entropy generation for an element under a specific inlet total pressure， inlet total temperature and outlet static pressure.