Reconstruction For The Gas-liquid Flow Of Liquid-ring Pump Based On Proper Orthogonal Decomposition

The liquid ring vacuum pump is a fluid machinery used for pumping gas,it has many advantages such as simple structure,component not directly contact,low temperature,so it is widely used for transport flammable and explosive,toxic gases,and industry,coal,metallurgical and pharmaceutical industries use it common According to the complicated gas-liquid flow in liquid-ring pump,the large amount of calculation,and the difficulty for its optimization design,the flow field reconstitution for the gas-liquid flow of liquid-ring pump based on proper orthogonal decomposition is proposed.To reconstruct the objective blade flow domain.1.Structured mesh,unsteady VOF method,ideal gas model,the PISO algorithm was used to simulate the liquid ring vacuum pump,analyzes its internal flow,the prediction of liquid ring pump characteristics and experimental results were compared to verify the feasibility of the numerical simulation method.2.The blade was parameterized by Taylor polynomial,and the experiment samples can be designed by introduce small perturbation of the control parameter.the parameters of the initial blade profile of disturbance and get the initial sample set by the internal flow field parameters and the corresponding control parameters for each sample is composed of a large sample set by POD method of sample data feature extraction.3.According to the geometric similarity of the impeller flow passage and the mesh deformation technology,the flow field data of the similar position of each point were interpolated.The snapshot set can be decomposed as linear combination of orthogonal basis by using proper orthogonal decomposition.The coefficients of the objective blade orthogonal basis were fitted by least square method.4.Reconstruction of velocity field and pressure field distribution is accurately,except for some errors exist near the wall and interface of gas and liquid in the blade outlet,the most area of the relative velocity error is about 0.2m/s.pressures error is around 1.7%-3.4%,the average error of volume fraction is about 0.013.5.In the calculation case for the type of 2BE-203 liquid-ring pump,the gas-liquid flows of single blade passage were reconstruction,and almost all the flow structures were accurately predicted.The prediction has high accuracy except near the gas liquid interface.The calculation amount for the multiphase flow field is greatly reduced.