Accession Number : ADA194490

Title :   A Mapping of the Viscous Flow Behavior in a Controlled Diffusion Compressor Cascade Using Laser Doppler Velocimetry and Preliminary Evaluation of Codes for the Prediction of Stall.

Descriptive Note : Doctoral thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Elazar, Yekutiel

PDF Url : ADA194490

Report Date : Mar 1988

Pagination or Media Count : 252

Abstract : Detailed measurements were made at M=0.25 and Re sub c = 700000 of the flow through a linear compressor cascade of controlled diffusion (CD) blading using a two-component argon-ion laser doppler velocimeter system. The measurements included mapping of the inviscid flow in the passage between two adjacent blades, boundary layer surveys, and wake surveys. Viscous flow phenomena such as a laminar separation region with reattachment on the suction surface, and laminar to turbulent transition on the pressure surface were resolved, and the viscous growth to the trailing edge was defined for three inlet angles from design incidence to near stall. Numerical calculations to predict the flow were carried out using a fully developed boundary layer code, a strongly interactive viscous inviscid code and a Navier Stokes code. It was shown that the common weakness of numerical predictors was in the modelling of transition and turbulence. The documented data can be used generally to calibrate compressor cascade analysis codes and thus enable reliable predictions of stall. Keywords: Laser doppler velocimeter measurements; Viscous cascade flow; Controlled diffusion blading; Code verification; Theses.

Descriptors :   *COMPRESSORS, *STALLING, *CASCADE STRUCTURES, ANGLES, BLADES, BOUNDARY LAYER, CODING, COMPUTATIONS, CONTROL, DIFFUSION, DOPPLER SYSTEMS, FLOW, GROWTH(GENERAL), INLETS, INTERACTIONS, INVISCID FLOW, LAMINAR FLOW, LASER VELOCIMETERS, MEASUREMENT, NAVIER STOKES EQUATIONS, NUMERICAL ANALYSIS, PREDICTIONS, PRESSURE, REGIONS, RELIABILITY, SUCTION, SURFACES, SURVEYS, THESES, TRAILING EDGES, TRANSITIONS, TURBULENCE, VISCOSITY, VISCOUS FLOW, WAKE, FLOW SEPARATION

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE