Tool Path Planning Of Moving Along The Fluidflow Direction On Propeller Blade Sueface In Machining Process

The propeller is the core components of large ships, submarines and other heavy powermachinery, and its performance has a direct impact on or even determines the overallperformance. Propeller noise and vibration affect the ship’s sailing safety passenger comfort.The submarine’s propeller noise seriously affects their covert. CNC machining of propellerwill leave marks and other surface defects. Surface defects affect fluid flow of propeller. It’sprone to unstable flow in the part near the blade surface, and the blade is easier to lead tovibration and noise. It has the greatest impact when the direction of fluid mechanical surfacedefects is perpendicular to the flow direction of the fluid, and it has the minimal impact whenthe direction of defects is parallel to the flow direction. Tool path planning of propellerconsidering flow field analysis can form a tool path coinciding with fluid flow line. This canreduce vibration and noise in a large degree.Propeller machining tool path planning based on flow field analysis described in this article,begin with the relevant technology of three-dimensional. First of all, we analyze the propellerdesign, modeling theories and calculate data points available for three-dimensional modelingcoordinates. We create the three-dimensional model of propeller through the Pro/E software,and the main steps include: import data points, generate blade surfaces, createhubandmaterialized. This paper proposes some improvements of propeller three-dimensionalmodeling.This paper employs CFD software FLUENT to numerically compute the viscous flow fieldof propeller. At first we imported three-dimensional model of propeller in GAMBIT, build upthe computational field of flow and mesh the field into discrete unstructured grids. Wecomplete the flow field analysis and draw three-dimensional flow field pattern of bladesurface after setting the boundary conditions, solving and calculation parameters.The propeller blade surface can be divided into three areas (trailing edge and blade back,leading edge and blade leaf, hub and blade root) in the first of Cutting tool path planningprocess.With trailing edge and blade back didn’t get high pressure at work, its cutting toolpath planning using parameter line method to get a higher computing speed. Cutting tool pathof hub is helix. Because the leading edge and leaf area work under high pressure, cuttingimperfections on the surface have serious influence on the working performance. Machiningtool path is the same direction as the blade surface flow, to reduce the influence of machiningsurface imperfections on working performance,so as to achieve the vibration and noisereduction purposes.The machining cutting tool path planning method described in this paper is based on thestructural feature of fluid machinery and fluid motion direction. This method combine thepropeller blade machining process with design process and working condition. The tool path planning consider in the direction of fluid motion on the surface of the blade, and intend toplan out cutting tool path which is in conformity with the fluid motion direction. This methodreduces effection of the blade micro smoothness on the stability of fluid flow, give full play tothe ability of machine tools. Propeller machining in this way can work more stable and moreconcealment.