Research On Automatic Modeling, Simulating And Optimizing Technologies For Bidirectional Throttle Flowmeter With Internal-and-External Tube

The differential pressure(or throttle)flowmeter is low in price but big in pressure loss,which is used widely in flow measurement of various industrial products.As a new type of differential pressure flowmeter,the bidirectional throttle flowmeter with internal-and-external tube has many advantages,such as small disturbance to the fluid,large differential pressure to measure and the bidirectional measurement.However,the optimization of the structural parameters for bidirectional throttle flowmeters with internal-and-external tube is not developed well.The traditional methods can either optimize the single structural parameters individually or 2~3 structural parameters at the same time.The design testing,modeling and simulating work is huge and low in efficiency.Aimed at the structural optimization of bidirectional throttle flowmeter with internal-and-external tube,this paper proposes a multi-parameter simultaneous optimization scheme to realize automatic modeling,simulation and optimization on the basis of multi-software joint.Firstly,a performance factor was presented to evaluate the bidirectional throttle flowmeter.Based on the fluid mechanics,the factors were analyzed to affect the performance of the pressure difference in the internal-and-external tube,and then 6 structural parameters were determined to be optimized,including the throttle tube length,the tapered cone length,the large tube length,the large tube diameter,the ratio of small by large diameter and the throttle thickness.After 27 orthogonal experimental tests designed,6 structural parameters were sorted according to the performance influence,and five of them were seleted to prepare for optimization except the throttle thickness.Secondly,it were carried out to modeling and simulate the bidirectional throttle flowmeter with internal-and-external tube automatically.Using SolidWorks as a platform for automatic modeling,VB.NET was seleted for the secondary development;COMSOL was taken as the platform of automatic simulation after setting up the physical field for the fluid simulation,the meshing method and the solver to complete the automatic simulation.Simulation results of COMSOL were compared with those of FLUENT and SolidWorks Flow Simulation to verify the accuracy of the COMSOL simulation results.The automatic modeling system,automatic simulation system and particle swarm optimization algorithm are integrated by MATLAB,and a complete automatic modeling,simulation and optimization system for bidirectional internal and external tube pressure difference flowmeters is established.The runtime program gets and verifies the optimized simulation results.And the impact of adding different weights on the optimization results is analyzed.Finally,the three-dimensional model is established by using the optimal structural parameters,and the prototype is made for experimental measurement.The experimental results are basically consistent with the simulation results.The automatic modeling,simulation and optimization techniques of the bidirectional throttle flowmeter with internal-and-external tube have high reliability.This paper provided a new idea for the multi-parameter simultaneous optimization of bidirectional throttle flowmeter with internal-and-external tube,which not only improved the optimization efficiency of flowmeter structural parameters,but also provided a new approach to simultaneous optimization of multi-parameters for other mechanical devices related to fluid mechanics.