Date of Award

12-1994

Degree Name

Master of Science in Engineering

Department

Mechanical and Aeronautical Engineering

First Advisor

Dr. Daniel J. Dorney

Second Advisor

Dr. Parviz Merati

Third Advisor

Dr. Iskender Sahin

Access Setting

Masters Thesis-Open Access

Abstract

It is known that in-service turbomachinery blades do not have uniform shapes. There are small differences due to blade erosion, manufacturing tolerances, or faulty installation. These differences can be in the size, shape, or relative angles of the blade. In an effort to predict losses resulting from changes in blade thickness and/or blade angles, a two-part investigation has been conducted. A two-dimensional unsteady Navier-Stokes flow analysis has been used to perform numerical experiments.

First, simulations were performed for an isolated cascade. One of the two stators was scaled and/or rotated. Results of the numerical simulations show that increasing the blade scaling causes higher total pressure losses compared to any rotation or reducing the scaling of the blades. The predicted numerical results show very good agreement with the available experimental data.

Second, turbine stage flow simulations were performed. One of the two rotors was scaled and/or rotated. Results of the turbine stage simulations show that the efficiency decreases almost 1.0% due to the scaling and rotation of the blade.

The significance of the results is that operational turbine blades must be well-maintained to minimize losses and maximize efficiency.

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