Study On The Key Technologies Of Performance Evaluation System For Hydraulic Manifold Block

Hydraulic Manifold Block(HMB) is the key part of the integrated hydraulic system, and energy loss and working performance of the hydraulic system are directly influenced by the flow performance. For engineering application, the design result of HMB need have good structure and the performance in according with the fixed design demand of hydraulic system. Combination with the National Natural Science Foundation project and taking permormance optimization baesd on structure optimization for object, the microcosmic flow and energy-loss mechanism is systematically investigated, and the design rules for enhancing through flow quality are established in the paper. Based above, the permormance appraisal and result optimization are achieved. And that the resistance characteristic of the design scheme is validated. The prospective achievements are obtained.After summarizing the research status at home and abroad, the optimization strategy is put forward to performance optimization by performance evaluation for structure design result population. It is a complex optimization design problem with muti-performance constraints which are derived from the thorough research on the hydraulic pipe flow, and belongs to the research category of hydrodynamics.According to the function requirements of performance evaluation system for HMB, a detailed planning is carried out based on functional driven system planning principle,including design scheme evaluation, performance appraisal and optimization, and performance validation. The architecture and work flow of the system are established.Based above, the key Computational Fluid Dynamics (CFD) technology for investigating on pipe flow mechanism inside HMB is presented, in accordance with the structure characteristic of the pipe inside HMB and the physicochemical properties of hydraulic pipe flow. The method possibility and the results reliability are validated by experiments.The work lays a foundation for the the paper.According to the characteristic of low Reynolds number inside hydraulic pipe flow, the computation modle of the local resistance number is established by the equivalent flow field and the distributed method, and the local resistance number at low Reynolds number are obtained. The resistance characteristic of local block is furthmore quantified, and the rules are reasonably explained. All local loss is included in the mothod, and the influence of wall on fluid is eliminated. The computation efficiency and the accuracy of local resistance coefficient are enhanced. Based above, the hydraulic pipe-flow characteristic and energy-comsuption mechanism are analyzed, and the structure design rules for local block inside HMB are determined to improve the throughflow performance.To comprehensivly evaluate the throughflow performance of the complex pipe inside HMB, the dimensionless pressuredrop coefficient and dissipation rate are used for evaluation index of resistance characteristic and energy-comsuption characteristic.by the CFD research on the typical complex channel, the complicated mechanism is revealed, and the nonlinear influence is analyzed. The influence of combination mode, attribute of aid hole and the input and output hole are described, and the throughflow quality of three combination channels are quantitatively evaluated. The structure design rules are determined for performance optimization of HMB. In addition, the virtual block rules are established for complex channel with fabrication holes, and its provide reference for engineering personnal to quickly analyze the complex flow characteristic.To realize the optimization for HMB results population, the optimization stratety based on Multi-Object Decision-Making method is presented. The perforamance constraints rules are converted to performance subgoals, and the Multi-Object Decision-Making model for HMB performance quality is established by linear weighted method.According to the original design data for performance optimization, the data structure is scientifically designed. From the requirement of performance optimization design, the engineering database system is built up. The automatic recognition of channel feature is achieved by database technology to appraisal the performance of the design scheme. The performance quality is quantitatively evaluated by the judgement result. The good scheme is determined by comparison with evaluation function value of the result sample.To calibrate the performance quality of HMB fastly and accurately, CFD in combination with Least Square Support Vector Machine (LS-SVM) is used to build the parametric model for pressuredrop prediction of channel. Based on the basic research by CFD, the parametric driving variables are determined, the training date and test date of the model are obtained by Orthogonal Experiments, and the pressuredrop prediction model is established with the kernel of LS-SVM model. By contrast, the kernel function suitable for pressuredrop prediction of channel is determined. The model is also compared with the prediction model based on BPNN in prediction accuracy, the number of necessary training samples and the training time. Practical tool software is successfully developed for engineering application to predict the pressurdrop of channel inside HMB.Based above research, VC++6.0 developing environment and ObjectARX developing toolkit are used to realize the connection and package of every submodules, the performance evaluation system is developed based on MDT software, and the performance optimization of the HMB design results are successfully achieved. Data input module, performance evaluation and selection module, and performance verification module of pipeline are incuded in the system. The effectiveness of the system and the feasibility of the method applied in the paper are validated by typical engineering example.