Test Research On The Hydrodynamic Property Of Hydraulic Machinery Fundamental Airfoil

Blade is an important part of hydraulic machinery which is converted the kinetic energy of the flow into mechanical energy,the dynamic characteristics of blade directly concerns the efficiency and service life of hydraulic machinery,decided the exertion of its economic benefits.Investigating the dynamic characteristics analysis and formation mechanism research of the hydraulic machinery can provide technical guidance for safe and efficient operation,it has important scientific significance.Three different parameters of joukowsky airfoil were acted as test object in this paper,searching the surface stress,lift,drag and hydrodynamic characteristics parameters through test of the different parameters of the airfoil at different flow,studying the changing law of the hydrodynamic characteristics parameters along with the angle of attack and the flow,The main research content and conclusion of the article contains the following several aspects:(1)we need to develop the test plan and set the hydrofoil experiment platform according to the test requirements,design and manufacture the test pipeline and control device which is used for rotating the angle of attack,choose the stress and strain acquisition instrument and waterproof strain gauge on the basis of meeting the test conditions,pasting strain gauge according to the requirements in the process of test which can guarantee the accurate and reliable of the test data;(2)Doing the testing experiment of the blade's surface stress of the three different parameters of joukowsky airfoil under different angle of attack and flow velocity,analyzing the hydrodynamic characteristics of the airfoil changing with the angle of attack and the flow and drawing the related curves;(3)Carrying on the numerical simulation of the NACA2408 airfoils,and analyzing the numerical simulation results;(4)Make a comparison of the test results and the results of numerical simulation,analyzing the similarities and differences of the two and probing into the reasons.The results of the two show that the test is an effective method to research hydrodynamic characteristics of fundamental airfoil.After the test,we study the distribution of hydrodynamic property of the blade,explore the change law of the blade airfoil along with the angle of attack and flow velocity,to get the lift coefficient curve and drag coefficient curve of the airfoil,laying a foundation for studying the hydrodynamic characteristics of complex shape blade.