Accession Number : ADA309389

Title :   Expansion of Kemp-Sears Unsteady Lift Predictor for Turbomachinery.

Descriptive Note : Technical rept.,

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK APPLIED RESEARCH LAB

Personal Author(s) : Lysak, P. D. ; Marboe, R. C.

PDF Url : ADA309389

Report Date : MAY 1996

Pagination or Media Count : 54

Abstract : A computer model which evaluates the unsteady forces acting on a three-dimensional blade has been developed using the theory of Kemp and Sears. Based on an existing computer model which performed unsteady lift calculations for a two-dimensional cascade of airfoils, the expanded model breaks the three-dimensional stator and rotor blades into a series of radial sections which are then evaluated as two-dimensional cascades. A user of the model can investigate how the magnitude and phase of the unsteady lift changes along the radius of the blade and determine the total unsteady blade forces acting in the axial and tangential directions. The computer model has been implemented in Mathcad version 6.0+, by MathSoft Inc., and can be used as an interactive design tool. The theory and implementation of the prediction model are discussed in this document. A brief overview of the Kemp-Sears theory and its simplifying assumptions is presente before a more thorough discussion of the three-dimensional blade geometry and the steps involved in breaking it down into cascade sections. In addition, the benefits of using Mathcad to implement the model are mentioned, and some ways of using the predictor are recommended.

Descriptors :   *UNSTEADY FLOW, *AERODYNAMIC LIFT, *PROPELLER BLADES, COMPUTER PROGRAMS, MATHEMATICAL MODELS, ALGORITHMS, COMPUTERIZED SIMULATION, LOAD DISTRIBUTION, INPUT OUTPUT PROCESSING, VORTICES, FLOW FIELDS, MATHEMATICAL PREDICTION, INTERPOLATION, WAKE, TWO DIMENSIONAL FLOW, INVISCID FLOW, VISCOUS FLOW, PRESSURE DISTRIBUTION, INCOMPRESSIBLE FLOW, AXIAL LOADS, TURBOMACHINERY, THREE DIMENSIONAL FLOW, CASCADES(FLUID DYNAMICS), ROTOR BLADES(TURBOMACHINERY).

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE