This thesis collates the state of the art for flow induced excitation in a turbomachine stage under subsonic incompressible flow conditions. Theoretical developments are considered first, beginning with the vortex theories of Kemp and Sears, Henderson, Horlock and Holmes. Actuator disk analyses of Whitehead, Henderson and Horlock, and Horlock, Greitzer and Henderson are then considered followed by field theories of Osborne, Warner and Steele. Computer programs based on these theories are described and detailed input/output instructions are given. Results of these theories are compared and the state of the art for theoretical prediction of nonsteady blade loading is discussed. It is concluded that the selection of an appropriate analysis is dependent on the stage geometry and on the type of excitation, i.e. low per revolution or nozzle passing excitation.
The theoretical development of the hydraulic analogy is discussed. Experimental studies of turbomachine stage flow by Harleman and Ippen, Heen and Mann, Johnson, Bryant, Owczarek, and Rhomberg are described. The development of the RIT rotating water table is also described. Water table tests, designed to determine the agreement between theoretically and experimentally predicted nonsteady loading of turbomachine blades are described and sample results are given. It is concluded that the nonsteady blade loading results obtained from water table tests compare favorably with those obtained from state of the art theoretical analyses for nozzle exit Mach numbers above 0.5. For Mach numbers below this value viscous effects become significant, and further studies to evaluate the accuracy of the hydraulic analogy under such conditions are recommended.
Library of Congress Subject Headings
Mechanical Engineering (MS)
Department, Program, or Center
Mechanical Engineering (KGCOE)
Neville F. Rieger
Crofoot, James F., "Theories and experiments for determination of nonsteady loads on turbomachine blades" (1979). Thesis. Rochester Institute of Technology. Accessed from
RIT – Main Campus