Download or read book Analysis of Turbine Rotor Tip Clearance Losses and Parametric Optimization of Shroud written by William V. Banks (III) and published by . This book was released on 2019 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerodynamic losses due to tip leakage in a High Pressure Turbine (HPT) rotor setting are analyzed using the commercial CFD software Star-CCM+. The compressible RANS equations were solved over unstructured polyhedral grids of 11 to 17 million cells, with turbulence resolved using the k-w SST model. A study of 3 blade tip/casing configurations at tip clearances between 0% and 4% of blade span is performed, with resulting mass-flow Reynolds #'s of 2.4-2.7 million and levels of reaction of 0.13-0.17. A flat-tip blade experienced a linear correlation between tip clearance and efficiency. The same blade with recessed casing was more efficient for small clearances, but large shear losses were seen to nullify this advantage at high clearances. A shrouded blade was more efficient than both at all clearances, displaying asymptotic behavior at high clearances. Various pressure and velocity monitoring techniques are employed to evaluate leakage flow and loss. Location and strength of leakage vortices are discussed, as these are closely tied with efficiency. A parametric study was performed on the shroud geometry, examining seal angle, number of seals, seal wear, and shroud axial gap. Efficiencies were compared between each study point at clearances of 2% and 4% of blade span. Total pressure loss was tracked across the blade and split between the main flow path and tip gap to distinguish between Profile and Internal Gap Shear losses. Axial gap was seen to have the greatest impact on efficiency, as a narrower gap acts as additional tip flow blockage and increases efficiency. At lower clearances, seal wear produced a negative impact as well.
Download or read book Numerical Analysis of Blade Tip Leakage Flow and Shroud Heat Transfer in Gas Turbine Engines written by Md. Hamidur Rahman and published by . This book was released on 2008 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Results of Varying the Blade shroud Clearance in a 6 02 inch Radial inflow Turbine written by Samuel M. Futral and published by . This book was released on 1970 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Three dimensional Analysis of Turbine Rotor Flow Including Tip Clearance written by R. Heider and published by . This book was released on 1993 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Preliminary Investigation of Hollow bladed Turbines Having Closed and Open Blade Tips written by Gordon T. Smith and published by . This book was released on 1955 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1975 with total page 1000 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Feasibility Study for a Practical High Rotor Tip Clearance Turbine written by Dennis C. Evans and published by . This book was released on 1972 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbine tip clearance loss prediction methods were investigated analytically. Vector diagram variations, flow path wall curvature, and stator tangential lean and axial sweep affect the magnitude of this loss for given turbine design requirements and tip clearance. For a model core turbine, a potential 30% reduction in clearance loss relative to an equivalent free vortex turbine is predicted for a practical application of these variations. A follow-on investigation is proposed. (Author).
Download or read book Aerodynamic Effect of a Honeycomb Rotor Tip Shroud on a 50 8 centimeter tip diameter Core Turbine written by Thomas P. Moffitt and published by . This book was released on 1983 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Axial Turbine Loss Analysis and Efficiency Prediction Method written by Yong S. Hong and published by . This book was released on 1966 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method is presented to predict axial stage turbine efficiency using detailed aerodynamic component losses. Suitable computer programs were set up for the more time consuming portions of the calculations. Boundary layer theory plus empirical test data was used to obtain numerical values for the flow losses. The method was applied to typical Boeing turbine tests and stage efficiencies were compared with the measured values. Calculated and measured stage efficiencies agreed within plus or minus one percent in all cases. This achievement proved to be far superior to existing prediction methods which yielded efficiency accuracies ranging from 2 to 7 percent. Using the developed method, the performance of a given turbine stage can be optimized without spending an excessive amount of time for numerical calculations by evaluating various combination of aspect ratio, solidity, number of blades, trailing edge thickness, and rotor tip clearance. All the investigated cases were checked for only single stage axial turbines. The accuracy of the method for multi-stage application has yet to be verified by experiment. (Author).
Download or read book Axial Turbine Aerodynamics for Aero engines written by Zhengping Zou and published by Springer. This book was released on 2018-01-11 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a monograph on aerodynamics of aero-engine gas turbines focusing on the new progresses on flow mechanism and design methods in the recent 20 years. Starting with basic principles in aerodynamics and thermodynamics, this book systematically expounds the recent research on mechanisms of flows in axial gas turbines, including high pressure and low pressure turbines, inter-turbine ducts and turbine rear frame ducts, and introduces the classical and innovative numerical evaluation methods in different dimensions. This book also summarizes the latest research achievements in the field of gas turbine aerodynamic design and flow control, and the multidisciplinary conjugate problems involved with gas turbines. This book should be helpful for scientific and technical staffs, college teachers, graduate students, and senior college students, who are involved in research and design of gas turbines.
Download or read book ASME Technical Papers written by and published by . This book was released on 1998 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer in Gas Turbine Systems written by Richard J. Goldstein and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explores recent developments in heat transfer and thermal control applied to modern high-temperature gas turbine systems. It examines experimental results and techniques computational studies and methods and design recommendations. Aspects of heat transfer in rotating machinery are studied as well as thermal aspects of other sections of the turbine (e.g. the compressor). Proceedings of an August 2000 conference.
Download or read book Effects of Axial Turbine Tip Shroud Cavity Flow on Performance and Durability written by Timothy Richard Palmer and published by . This book was released on 2015 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow through tip shroud cavity in a representative axial turbine vane-rotor stage environment is assessed for its role in loss generation and turbine durability. Steady and unsteady three-dimensional flow computations, complemented by control volume analyses, for varying shroud configurations provided results for establishing quantitative links between loss and ow processes as well as loss level scalings. Specifically tip shroud cavity flow is dominated by two counter-rotating vortices upstream, and a free expansion leakage jet downstream, of the tip seal, followed by a mixing shear layer at cavity exit. One of the vortices, the cavity inlet toroidal vortex, sets the loss level within the cavity inlet and the mass ow recirculated out of the cavity into the main flow path. It is found that tip shroud cavity flow incurs a 0:85% debit in stage eciency per 1% of main flow fluid through the cavity with approximately 50% generated in the free expansion of the tip seal leakage jet and 50% from cavity exit mixing. The proportion of total loss attributable to cavity exit mixing increases with tip seal gap. In addition, vane-rotor unsteady interaction induces an additional 0:25% debit in eciency per 1% of main flow fluid through the cavity. The additional efficiency penalty induced by vane-rotor unsteady interaction results from an enhancement of the cavity inlet toroidal vortex and associated recirculated mass flow. Overall cavity loss is set by cavity mass flow fraction, stagnation pressure ratio across tip seal, velocity disparity between cavity exit flow and rotor exit flow, and cavity inlet vortex strength. These findings were used to formulate a modified tip shroud configuration that nearly eliminates cavity exit mixing loss, but it incurs a penalty associated with cavity flow low Reynolds number effects and induced mismatching between vane and modified tip shroud. In the process of designing this modified tip shroud, it was found that the turbine main flow perceives the cavity as a line sink-source pair, permitting estimation of flow redistribution in the main flow path. Finally, any operational transients which eliminate tip seal clearance would lead to enhanced impingement heat transfer at blade tip due to recirculating ow from cavity inlet; this can increase the likelihood of blade failure.
Download or read book Paper written by and published by . This book was released on 1998 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gas Turbines for Electric Power Generation written by S. Can Gülen and published by Cambridge University Press. This book was released on 2019-02-14 with total page 735 pages. Available in PDF, EPUB and Kindle. Book excerpt: Everything you wanted to know about industrial gas turbines for electric power generation in one source with hard-to-find, hands-on technical information.
Download or read book Turbine Tip Clearance Loss Mechanisms written by Steven Andrew Mazur and published by . This book was released on 2013 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three-dimensional numerical simulations (RANS and URANS) were used to assess the impact of two specific design features, and of aspects of the actual turbine environment, on turbine blade tip loss. The calculations were carried out for a subsonic high pressure turbine stage. The loss mechanism examined is that due to tip clearance vortex mixing. The effects examined were three-dimensional blade stacking, downstream transition duct geometry, and unsteadiness due to an upstream nozzle guide vane. Tip leakage loss changes due to three-dimensional blade stacking (bowing or reverse bowing) are verified to be associated with changes in the magnitude of blade tip loading, which create differences in the leakage flow exit velocities. The effect of a downstream diffusing transition duct on tip leakage losses is small; there was a 3.6% increase in tip leakage loss for a 65% increase in duct exit-to-inlet area ratio compared to a constant area duct. For unsteadiness arising from an upstream nozzle guide vane, it is shown that substantial temporal fluctuations in vortex core velocity and loss generation exist. However, the time average tip leakage loss differed less than 5% from the tip leakage loss calculated on a steady flow basis. Based on the computations, the mechanism for tip leakage vortex loss in the three different situations examined appears to be similar to that which is seen for an isolated turbine blade.
