Research On Application Of Reverse Engineering To Reverse Design Of Closed Impeller

In the mid-age of the 20 century, the method of matter reverse, namely reverse engineering, appeared in order to digest and absorb advanced technique abroad and check parts of complex curved surface. From available models, the method firstly does 3D digital measurement to the model and reviews CAD model using the data, then does CAE analysis, improvement and innovation, and makes new product in the last. The paper tells about detailed operation of reverse engineering aiming at closed impeller including complicated cavities.In the first place, it introduces method of forward design of closed impeller. The method turns out structure size of impeller and coordinate figure of shaped lines of vane based on property parameter ( quantity of flow, total head, power, rotation rate, etc), then draws axis projection chart of impeller and imageclip of vane using the data. Just it has a range of coordinate figure of height H and radius R of the former and back plates of impeller, it can draw projective axis chart of impeller from forward design analysis. Set axis surface of H, relatively measure polar coordinates figure( angleθand radius R) of intersection points of axis surface from different angles and working surface, no-working surface, and then draw cylinder coordinate imageclip of vane.Based on the facts of middle and small manufacture corporation, the paper introduces data acquisition of closed impeller using coordinate boring or milling machine, specially elastic probe, universal power meter, etc. the principle of data acquisition is same to that of three dimensional measuring machine. Just compounding with tools such as specially elastic probe and universal power meter, the data in the impeller flow road is measured. It plans proper measurement areas and curves which is the lines of forward, back plate of impeller flow road, the working and no-working surface after analyzing the function and principle of impeller. It rebuilds impeller model using positive CAD software without reverse software doing with the data and'point clouds'data.The paper introduces rebuilding method of impeller model which checks, analyzes and corrects the original curves using curves function of Solidworks. The method extends working and no-working surfaces of vanes which are got by lofting to forward and back plates of impeller, and obtains intersect surface of vanes and forward, back plates to bring about seamless combination of vanes and forward, back plates and to take convenience to following quality, volume measurement and CAE analysis.it can realize that shaped curves of vanes are designed by parametre driving through reading 3D coordinate points of curves to conveniently amend or innovate impeller.The impellers which rebuild conversely are made flow analysis by Solidworks flow simulation. It gains velocity and isostatic pressure distribution diagram of inner impeller by numerical simulating flow field. It can get liquid pressure and speed of impeller export from the distribution diagrams. Pressure can obtain total head, speed gets flow quantity, and inlet, outlet pressures and flow quantity can get power. Compare the data with corresponding parameters of original sample to check conformance of rebuilding and original impellers to judge whether converse engineering succeeds or not.