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Book NASA Technical Paper

Download or read book NASA Technical Paper written by and published by . This book was released on 1983 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book NASA Scientific and Technical Publications

Download or read book NASA Scientific and Technical Publications written by and published by . This book was released on 1987 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Bibliography of Lewis Research Center Technical Publications Announced in 1983

Download or read book Bibliography of Lewis Research Center Technical Publications Announced in 1983 written by and published by . This book was released on 1984 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Reasons for Low Aerodynamic Performance of 13 5 centimeter tip diameter Aircraft Engine Starter Turbine

Download or read book Reasons for Low Aerodynamic Performance of 13 5 centimeter tip diameter Aircraft Engine Starter Turbine written by Jeffrey E. Haas and published by . This book was released on 1981 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation was made at the NASA Lewis Research Center to determine the reasons for the low aerodynamic performance of a 13.5-centimeter-tip-diameter aircraft engine starter turbine. The investigation consisted of an evaluation of both the stator and the stage. An approximate 10-percent improvement in turbine efficiency was obtained when the honeycomb shroud over the rotor blade tips was filled to obtain a solid shroud surface. (Author).

Book NASA Scientific and Technical Publications

Download or read book NASA Scientific and Technical Publications written by and published by . This book was released on 1987 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book NASA SP

    NASA SP

    Book Details:
  • Author :
  • Publisher :
  • Release : 1962
  • ISBN :
  • Pages : 396 pages

Download or read book NASA SP written by and published by . This book was released on 1962 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Experimental Performance and Analysis of 15 04 centimeter tip diameter Radial inflow Turbine with Work Factor of 1 126 and Thick Blading

Download or read book Experimental Performance and Analysis of 15 04 centimeter tip diameter Radial inflow Turbine with Work Factor of 1 126 and Thick Blading written by Kerry L. McLallin and published by . This book was released on 1980 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Turbine Tip and Shroud Heat Transfer

Download or read book Turbine Tip and Shroud Heat Transfer written by Darryl E. Metzger and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unshrouded blades of axial turbine stages move in close proximity to the stationary outer seal, or shroud, of the turbine housing. The pressure difference between the concave and convex sides of the blade drives a leakage flow through the gap between the moving blade tip and adjacent wall. This clearance leakage flow and accompanying heat transfer are of interest because of long obvious effects on aerodynamic performance and structural durability, but understanding of its nature and influences has been elusive. Previous studies indicate that the leakage through the gap is mainly a pressure-driven flow whose magnitude is related strongly to the airfoil pressure loading distribution and only weakly, if at all, to the relative motion between blade tip and shroud. A simple flow and heat transfer model incorporating these features can be used to estimate both tip and shroud heat transfer provided that reasonable estimates of the clearance gap size and clearance leakage flow can be made. The present work uses a numerical computation of the leakage flow to link the model to a specific turbine geometry and operating point for which a unique set of measured local tip and shroud heat fluxes is available. The resulting comparisons between the model estimates and measured heat transfer are good. The model should thus prove useful in the understanding and interpretation of future measurements, and should additionally prove useful for providing early design estimates of the levels of tip and shroud heat transfer that need to be compensated for by active turbine cooling.

Book Effects of Axial Turbine Tip Shroud Cavity Flow on Performance and Durability

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.

Book Government Reports Announcements Index

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1983 with total page 962 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Effect of Rotor Tip Clearance and Configuration on Overall Performance of a 12 77 centimeter Tip Diameter Axial flow Turbine

Download or read book Effect of Rotor Tip Clearance and Configuration on Overall Performance of a 12 77 centimeter Tip Diameter Axial flow Turbine written by J. E. Haas and published by . This book was released on 1979 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: