應用逆向工程與計算流體力學檢測實驗螺槳

The Examination of an Experimental Propeller Utilizing Reverse Engineering and CFD

本文針對一顆4葉實驗螺槳探討其在加工製造後之幾何誤差對推進性能之影響。採用非接觸式雷射掃描之逆向工程技術特別應用於驗證該螺槳葉片在設計幾何與製造加工後之差異性。無黏度之Panel Method與商用軟體CFD亦進一步地計算其葉片上之壓力分佈狀況，並與實驗結果的照片作空蝕現象之比對。其相對應之推力係數與轉矩係數也同時探討其效應。最後，本文提供一有效之方法以驗證製造螺槳之幾何精度，同時也可預估該螺槳因製作誤差所引致的推進性能差異。 This paper adopts an experimental marine propeller with four-blades to investigate the effects of geometry discrepancy incurred by the manufacturing processes. A reverse engineering technology is utilized to particularly acquire the geometry discrepancy and validate the propeller geometry after fabrication-the measured geometrical data are further compared with those of the design propeller. Moreover, an inviscid panel method and the commercial CFD code are used to calculate the pressure distribution on the blades of the fabricated propeller. The resultant pressure distribution is thereby compared with the experiment in terms of cavitation phenomena. The thrust and torque coefficients are also investigated accordingly, In short, it is feasible to adopt the present methodology to inspect geometry and also predict the performances of manufactured propellers.