Date of Award

Summer 2014

Degree Type


Degree Name

Master of Science (MS)


Mechanical Engineering

First Advisor

Nicole L. Key

Committee Member 1

Eckhard Groll

Committee Member 2

Jun Chen


The objective of this research has been to design optical access for the application of laser Doppler velocimetry (LDV) in a low specific speed centrifugal compressor. The ability to acquire non-intrusive flow measurements will provide valuable insight into tip leakage flow, secondary flow, and impeller/diffuser interactions within the centrifugal compressor. The current research facility houses a new low specific speed centrifugal compressor which design is based off a compressor that would be installed as the last stage of a high-pressure compressor.

The LDV optical access has been designed and includes two fused silica windows that are housed in stainless steel holders and conform to the flow path of the compressor shroud. The two windows will allow three-component velocity measurements of 85% of the impeller flow path, the vaneless space, and two vaned diffuser passages. Finite element analysis (FEA) was performed in ANSYS to validate the stress and deflection of the shroud for the new window design. A manufacture has been selected to fabricate the window assemblies.

In addition to the design of the LDV optical access, several improvements have been made to the existing facility. Such improvements include the development of the facility oil system, the design of a new inlet plenum, and installation of the newly acquired centrifugal compressor. High precision measurement devices have also been adapted by the facility such as a long-form venturi, a high accuracy tip clearance measurement system, and a three-component LDV system. The current state of the facility has been documented. The design and capabilities of the research compressor have also been provided.