Film cooling by means of holes is an essential cooling technique in modern gas turbine engines. This cooling technique is employed over endwalls, as well as on the surface of blades. Thus, there is a need for film cooling predictions in a three-dimensional setting. Currently only boundary layer codes are available for design purposes and they are difficult to apply to the three-dimensional case with secondary flows. Present advanced computation prediction methods are capable of solving the complete flow field in three dimensions with coolant flow. However, the spatial resolution that these methods require eliminate them as suitable options for design tools This study introduces a simpler description of the film cooling process which may be implemented in a code for design purposes. The parameters of turbulence enhancement, turbulence decay, and the coolant distribution at injection were optimized using existing experimental data. Finally, the code was employed in a three-dimensional setting with film cooling present. An experimental study of the flow through cooling holes was also undertaken. Two unique geometries were later developed where a row of cooling holes exited into a vortex region where the flow was mixed before being injected from a slot. The cooling benefits of these geometries is apparent.

No description available.

Thesis (M.S.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph.D.)--Aerospace Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Hodges, Dewey H.; Committee Member: Bauchau, Olivier A.; Committee Member: Johnson, Ellis; Committee Member: Makeev, Andrew; Committee Member: Volovoi, Vitali V.

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, June 2005. / Thesis Advisor(s): Knox T. Millsaps. Includes bibliographical references (p. 73-74). Also available online.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Clearances between gas turbine casings and rotating blades is of quite importance on turbo machines since a significant loss of efficiency can occur if the clearances are not predicted accordingly. The radial thermal growths of the blade may be over or under predicted if poor assumptions are made on calculating the metal temperatures of the surfaces exposed to the fluid. The external surface of the blade is exposed to hot gas temperatures and it is internally cooled with air coming from the compressor. This cold air enters the radial channels at the root of the blade and then exists at the tip. To obtain close to realistic metal temperatures on the blade, the Conjugate Heat Transfer (CHT) approach would be utilized in this research. The radial thermal growth of the blade would be then compared to the initial guess. This work focuses on the interaction between the external boundary conditions obtained from the commercial Computational Fluid Dynamics software package CFX, the internal boundary conditions along the channels from a 1D flow solver proprietary to Siemens Energy, and the 3D metal temperatures and deformation of the blade predicted using the commercial Solid Mechanics software package ANSYS. An iterative technique to solve CHT problems is demonstrated and discussed. The results of this work help to highlight the importance of CHT in predicting metal temperatures and the implications it has in other aspect of the gas turbine design such as the tip clearances.

An accurate knowledge of turbine blade surface temperature is desired in order to obtain maximum performance from turbine engines. A limited spectrum radiation pyrometer can be used for blade temperature measurement. A model is presented which predicts the output signal from the detector unit of a pyrometer in a turbine engine application. Six inputs are required for the model. The inputs are the turbine blade geometry, location of the pyrometer with respect to the blades being viewed, focusing parameters of the pyrometer, type of detector, transmission curve of the optical system, and an estimate of the blade surface temperature. The model uses Fortran 77 and IBM CADAM to create a three dimensional representation of the pyrometer path across the blades along with the intercepted target spots. Once the target spot areas are determined, the photocurrent output signal of the detector is predicted as a function of percent blade chord and time. Results are shown for different detectors and temperature distributions. Experimental data is also included, and a comparison is made between the data and the model. Any of the model input parameters can be varied so that different pyrometer schemes can be evaluated at either the initial design phase or after installation. / Master of Science

A cross-flow turbine was tested to determine the magnitude of the fluid forces on the blades. The tangential and radial forces and the torque were measured on a test blade. Because the runner was made of plexiglas, the flow and the effects of the incidence angle at various speeds were observed. The pattern of blade loading over a revolution was measured over a range of heads from 1.0 to 2.6 m. The maximum forces were found to occur just before the blade leaves the nozzle exit. The experimental forces agree reasonably well with the results of a control volume analysis. Two figures are provided, by which the designer may determine the tangential and radial forces for any geometrically similar machine. / Master of Science

Past research at Virginia Tech (VPI) explored the aerodynamic loss of the transonic VPI turbine blade, which 1s based on the pitchline profile of a high pressure turbine blade for a large commercial aircraft gas turbine. The current experiment explores the loss of the VPI blade for different axial solidity ratios near the design point. Ten percent changes in the solidity ratio were accomplished by varying the blade pitch and changing the blade stagger to maintain a constant throat to spacing ratio. Reaction, exit angle and exit Mach number were kept constant with this method. Cascades with three different solidities were tested in VPI’s transonic blowdown wind tunnel. Downstream total pressure loss and static pressure measurements were obtained. In addition, inviscid calculations were made for each case. Static pressure contours and Mach number profiles from the calculations were compared with the experimental results. A ten percent decrease in solidity caused no cascade loss penalty as compared to the Baseline solidity for a wide range of Mach numbers. Calculated blade Mach number profiles agreed well with experimental profiles except on the suction side near the throat and downstream of the shock/boundary layer interaction. Predicted downstream static pressure values agreed well with experimental values, except that the inviscid code tended to over-predict the pressure rise across the suction side shocks. / Master of Science