Heat Transfer in Rotating Serpentine Passages With Trips Normal to the Flowстатья из журнала
Аннотация: Experiments were conducted to determine the effects of buoyancy and Coriolis forces on heat transfer in turbine blade internal coolant passages. The experiments were conducted with a large scale, multi–pass, heat transfer model with both radially inward and outward flow. Trip strips on the leading and trailing surfaces of the radial coolant passages were used to produce the rough walls. An analysis of the governing flow equations showed that four parameters influence the heat transfer in rotating passages: coolant–to–wall temperature ratio, Rossby number, Reynolds number and radius–to–passage hydraulic diameter ratio. The first three of these four parameters were varied over ranges which are typical of advanced gas turbine engine operating conditions. Results were correlated and compared to previous results from stationary and rotating similar models with trip strips. The heat transfer coefficients on surfaces, where the heat transfer increased with rotation and buoyancy, varied by as much as a factor of four. Maximum values of the heat transfer coefficients with high rotation were only slightly above the highest levels obtained with the smooth wall model. The heat transfer coefficients on surfaces, where the heat transfer decreased with rotation, varied by as much as a factor of three due to rotation and buoyancy. It was concluded that both Coriolis and buoyancy effects must be considered in turbine blade cooling designs with trip strips and that the effects of rotation were markedly different depending upon the flow direction.
Год издания: 1991
Авторы: J. H. Wagner, B. V. Johnson, Riccardo Graziani, F. C. Yeh
Источник: Volume 3: Heat Transfer; Electric Power; Industrial and Cogeneration
Ключевые слова: Heat Transfer Mechanisms, Turbomachinery Performance and Optimization, Fluid Dynamics and Turbulent Flows
Другие ссылки: Volume 3: Heat Transfer; Electric Power; Industrial and Cogeneration (HTML)
NASA STI Repository (National Aeronautics and Space Administration) (PDF)
NASA STI Repository (National Aeronautics and Space Administration) (HTML)
NASA STI Repository (National Aeronautics and Space Administration) (PDF)
NASA STI Repository (National Aeronautics and Space Administration) (HTML)
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