3D Inverse Design of Transonic Fan Rotors Efficient for a Wide Range of RPM

Abstract

Present paper contains application of inverse problem for 3D Navier-Stokes equations to design turbomachinery bladed rows. In-house software package used to solve 3D inverse problem is named 3D-INVERSE.EXBL. Inverse problem is based on desired static pressure distribution on suction side of blade, given blade thickness and pressure difference (named loading) in corresponding points of suction and pressure sides of blade. Inlet and outlet gas-dynamic parameters (pressure, density and flow velocity vector) are taken from direct solution of flow within multistage compressor and remains unchanged during inverse problem solution. Solution of inverse problem is determined using moving grid. Normal speed of face of grid cell adjacent to blade surface is determined using given static pressure (inverse mode) with the aid of relationships which are the elements of Godunov scheme applied for integration of flow equations. In the paper inverse solution provides effectiveness and operability of first rotor of multistage low pressure compressor (LPC) for a wide range of rpm (70 ± 100%) in case of absence of inlet guide vane (IGV).