Quasi 3-D Flow Design and Characteristics of Diagonal Flow Impeller with Circular Arc Plate

Basing on the principle of virtual equivalent velocity, this paper adapt the method of extending axis flow impeller to the quasi 3-D flow design of diagonal flow impeller with the experimental cascade data of circular arc blade. The performances of diagonal flow fan with outlet guide volute designed by this method, are compared with that designed by airfoil section cascade data. The reasonableness and reliability of this design method is verified. 1. Preface It is been pay close attention increasingly to design and application of diagonal flow fan with NACA65 airfoil section [1]. A series of the fan products has succeed in operating in industry. It shows a fair economical benefit to substitute an equal thickness circular arc plate for airfoil section blade, under cases of either operating fan at low pressure or simplifying manufacture and decreasing cost of production paying a little reduce of performance of fan. From this point, this paper research is shown as below. 2. Quasi 3~D Flow Design of Diagonal Flow Impeller with Circular Arc Blade (1). meridian surface calculation The streamline distribution of meridian surface Sz is found by use Novak Streamline Curvature Method (SCM) on equihl>rimn equation [2]of flow ration q along quasi-orthogonal line. c! = e-f A(q)dq[J B( q)J A(q)dq + C] integration constant C is determined by continues condition: