...Chia Hui Lim; Graham Pullan; John Northall A methodology is presented to allow designers to estimate the penalty for turbine efficiency associated with film cooling. The approach is based on the control volume analysis of Hartsel and the entropy-based formulations of Young and Wilcock. The present...

... a temperature difference and hence a density ratio of 1.3, while the blowing ratio is maintained at 2. The entropy change, derived from pressure and temperature measurements, is calculated by using modified reference conditions to better reflect the losses in both the jet and the freestream. The effects...

...S. J. Payne; A. J. W. Moxon The aspirating probe has recently been successfully used to measure entropy within a turbomachine; however, it was found that its sensitivity to total pressure and total temperature fluctuations was significantly altered at high frequencies. If the aspirating probe...

... conditionally sampled boundary layer data for zero pressure gradient and accelerating transitional boundary layers have been analyzed to calculate the entropy generation rate in the transition region. By weighting the nondimensional dissipation coefficient for the laminar conditioned data and turbulent...

... rational efficiency and can be directly related to the various cooling losses. However, as it gives a significantly lower value than the Hartsell and MP definitions, it may not appeal to turbine manufacturers. The WP definition is a pragmatic alternative. In the WP ideal process the entropy increase...

... transfer, and mixing of the coolant with the mainstream, are determined strip by strip along the whole blade chord for the stator and rotor of the stage and illustrated on an enthalpy-entropy chart. The work output from each rotor strip is obtained together with the losses (entropy creation) through...

...-2D results at midspan are comparable to the modern codes for the time-resolved and time-averaged pressure data, which is remarkable given the vast differences in the processing required. UNSFLO-2D models the entropy generated around the airfoil surfaces using the full Navier-Stokes equations...

... a moving shock wave that produces an entropy rise and loss is experienced. The effect of this outcome of blade-row interaction is to lower the efficiency, pressure ratio, and mass flow rate observed as blade-row axial spacing is reduced from far to close. The magnitude of loss production is affected...

... and disk cooling are suggested. There is confusion in the literature concerning cooling losses, and it is shown how these may be defined and subdivided in a consistent way. The importance of representing losses in terms of irreversible entropy creation rather than total pressure loss is stressed. A set...

...J. H. Horlock 09 04 2002 gas turbines cooling heat transfer entropy thermodynamics fluid mechanics The authors are to be commended for adding considerably to our understanding of the fluid mechanics and thermodynamics of turbine cooling. I would pick...

...Martin von Hoyningen-Huene; Alexander R. Jung This paper studies different acceleration techniques for unsteady flow calculations. The results are compared with a nonaccelerated, fully explicit solution in terms of time-averaged pressure distributions, the unsteady pressure and entropy...

... February 1999. Paper No. 99-GT-25. Review Chair: D. C. Wisler. 07 June 1999 01 February 1999 gas turbines stators wakes mixing temperature distribution pressure nozzles rotors flow simulation entropy computational fluid dynamics Turbomachinery designers have a wealth...