水力机械非定常流动内能变化与水力损失机理研究

本研究将试图建立水力机械水力损失与能量耗散之间的数学模型和数值分析方法，研究离心泵内部漩涡脉动流的水力损失、温度场和能量耗散的非定常特性，从水流内能变化角度评估水力损失和涡漩强度，并从内能变化上揭示离心泵不同运行工况下的水力损失机理。采用数理模型、数值模拟和模型试验相结合的分析方法，引入熵产、焓变等概念，分析离心泵内部流体介质能量转换与耗散过程，详细研究介质能量分布与转换定量表征的数学模型、局部涡漩结构强度、能量耗散与水力损失映射关系、温度场压力场非定常特性测量和计算分析。本研究从内能变化角度分析水力损失的机理，促进热力学研究方法在水力机械理论分析和试验方法中的应用，形成水力机械能量传输机理新的研究方法，可为水力机械尤其离心泵动量和能量守恒分析计算拓展新的途径，促进水力机械优化设计方法的进步。

This project proposes to build a mathematical model and numerical analysis method to study the hydraulic loss and energy dissipation, and investigate the unsteady characteristic of hydraulic loss, temperature field and energy dissipation in pulsatile vortex flow. In this research, the hydraulic loss and the intensity of local vortex flow are evaluated from the view of internal energy change, which will also illustrate the loss mechanism in centrifugal pumps under different working conditions. This project will carry out mathematical models with theoretical analysis, numerical simulation and model test in order to present energy conversion and dissipation by combining with thermodynamic concepts like entropy and enthalpy. The study will concentrate on quantitative analysis and mathematical model on energy conversion and distribution of the viscous fluid in the centrifugal pump, criterion research on the intensity of local vortex flow and energy dissipation analysis, relationship between energy dissipation and hydraulic loss, and simulation and test on unsteady temperature and pressure field. With a perspective of internal energy change, this project will promote the application of thermodynamic method in theoretical analysis and model test on hydraulic machines. A new method on the mechanism of energy transmission in hydraulic machines will be investigated, which will open up new vistas of the analysis on conservation of momentum and energy in hydraulic machines, especially in centrifugal pumps. This method could also improve the optimization design of hydraulic machines.