Research On Automatic Routing And Optimization Method For External Pipeline Of Aero-Engine

Pipeline system widely exists in all kinds of complex mechanical products.Aero-engine is a typical complex product that consists of hundreds of external pipes.Compared with the traditional model test design method,the automation of the design tools has been achieved to some extent through the traditional CAD-based human-machine interaction piping design approach.However,the construction of pipe digital model has been remained in the manual design stage,when designers complete the layout of pumps,valves,pipe connections and other accessories.There are many factors that affect the layout quality in the pipe design process.In addition to satisfying the requirement of feasibility,a series of requirements such as routing sequence,maintenance,assembly,manufacturing,interference,vibration characteristics and safety should also be comprehensively considered.Since the above factors often interact with each other,it is difficult to ensure the optimization of the design results.In order to improve the efficiency and quality of pipe routing design,the external pipe of aero-engine is taken as the research object,and the related theory,key technology and implementation method of automatic layout and optimization design are studied.The main research contents are as follows:(1)In this paper,the aero-engine pipe routing characteristics and the engineering constraints to be met in the actual design process are summarized.In addition,the mathematical description for processing various constraints in the optimization process is proposed,and the mathematical models of single pipe and multiple pipe layout optimization are established.(2)A layout space preprocessing method is presented.In this method,the obstacles and routed pipes are described separately in two different ways.For the accessory obstacles,the local grid matrix of each obstacle is established to automatically filter out the available routing space.For the routed pipes,the interference conditions of surface geodesic pipeline and 3D space pipeline are derived.(3)A sequential-based single pipe layout optimization method is proposed.Firstly,the traditional layered-based routing method is extended,and then an obstacle avoidance strategy is presented.Secondly,aiming at the disadvantage of BAS algorithm that easy to premature convergence and fall into the local optimum,an adaptive variable step mechanism is introduced to search for a better solution while keeping the efficiency of BAS algorithm to a certain extent.Finally,the feasibility and efficiency of the proposed method are verified by simulation experiments.(4)A multiple pipe routing optimization method focusing on parallel layout is proposed.Firstly,a compressed visibility graph(CVG)algorithm is constructed to rapidly determine the position and interference relationship between the pipes to be routed,and then pipes are grouped and sorted respectively by the clustering algorithm and the criterion of interference degree.Secondly,the co-evolution strategy is introduced into the DE algorithm to achieve synchronous optimization for the pipes in one group.Finally,the SA algorithm is used to complete parallelization processing for pipes.Simulation results show that the proposed method not only guarantees the efficiency and feasibility of the layout process,but also meets the requirement of parallel layout for multiple pipe system.(5)Based on the above theory,the automatic pipe routing software for aero-engine is developed.The software implements the functions of accessory interface definition and management,pipe grouping management,routing space definition,automatic pipe routing,pipe information export,etc.