Download or read book Discharge Coefficient of Inclined Film Cooling Holes with Rounded Entry and Crossflow written by S. E. Henshall and published by . This book was released on 1988 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Discharge Coefficient of Film Cooling Holes with Rounded Entries Or Exits written by A. Khaldi and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ASME Technical Papers written by and published by . This book was released on 2001 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paper written by and published by . This book was released on 2000 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Turbomachinery written by and published by . This book was released on 1994 with total page 800 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 1989 with total page 984 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of internal coolant crossflow orientation on the discharge coefficient of shaped film cooling holes ASME 99 GT 40 written by Michael Gritsch and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine & Aeroengine Congress & Exhibition, Indianapolis, Indiana, June 7-June 10, 1999.
Download or read book Discharge coefficient of film cooling holes written by B. V. Mellor and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Film Cooling with Ejection from a Row of Inclined Circular Holes written by Christian Liess and published by . This book was released on 1973 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Discharge Coefficient and Trends in Film Cooling Effectiveness of Conical Holes with Increasing Diffusion Angles written by Humberto A. Zúniga and published by . This book was released on 2006 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results and trends are compared with established literature, which also recommends that a cylindrical entry length for diffused holes should be at least 4 diameters long. The effect that an added entry length has on the 3-degree conical plate’s cooling effectiveness is also explored. Data are compared to baseline cylindrical holes, as well as to fan-shaped film holes found in open literature. Results indicate that the conical holes with larger diffusion angles provide strikingly even film protection and outperform fan shaped and cylindrical holes under certain conditions over extended downstream distances. Also, the addition of a cylindrical entry length to a conical hole, by providing a manageable metering diameter, should ease their usage while providing the full benefits of the conical geometry which may one day lead to numerous industrial applications.
Download or read book Streakline Flow Visualization of Discharge Hole Film Cooling with Holes Inclined 30 to Surface written by Raymond S. Colladay and published by . This book was released on 1976 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Flow Field Study of a Film Cooling Hole Featuring an Orifice written by Yingjie Zheng and published by . This book was released on 2014 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Film cooling is a jet-in-crossflow application in gas turbines used to protect high temperature parts. Understanding the physical phenomena in the flow field, for example the detrimental counter-rotating vortex pair, is highly critical. Experimental investigations were conducted using stereoscopic PIV to study the flow field downstream from film cooling holes featuring an orifice, under blowing ratios from 0.5 to 2.0. The original geometry of a short injection hole that was proposed in a previous numerical study was examined. The results reported a significant reduction in counter-rotating vortex pair strength of nozzle hole injection in comparison with cylindrical hole injection. The streamwise vorticity of the nozzle hole jet averaged a drop of 55% at a low blowing ratio of 0.5, and a 30%–40% drop at high blowing ratios of 1.0, 1.5 and 2.0. Due to the reduction in counter-rotating vortex pair strength, a round jet bulk was observed forming from the two legs of a typical kidney-shaped jet. The merged jet bulk delivered better coverage over the surface. The effect of the geometrical parameters of the orifice and the effect of the blowing ratio were also investigated using long injection hole geometry to isolate the impact of the short hole length. It was found that under high blowing ratio conditions, no structural difference occurred in the jet when altering the value of blowing ratio. The most important geometrical parameters were the opening width and the in-hole position of the orifice. The measurement results suggested that the width of the orifice had a major impact on downstream counter-rotating vortex pair strength, and the in-hole position of the orifice mainly affected the penetration characteristics of the jet. The mechanism of the counter-rotating vortex suppressing effect of the orifice was studied from the flow field data. It is proven that the orifice greatly eliminated the hanging vortices developing from the in-hole boundary layer vorticity, which was the major contributor to counter-rotating vortex formation in inclined jets.
Download or read book Discharge Coefficient Measurements of Film cooling Holes with Expanded Exits written by M. Gritsch and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine & Aeroengine Congress & Exhibition, Orlando, FL, Jun 2-Jun 5, 1997.
Download or read book Discharge Coefficient of Flared Film Cooling Holes written by N. Hay and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine and Aeroengine Congress and Exposition, Houston, Texas - June 5-8, 1995.
Download or read book Diffused exit Film Cooling Holes Fed by an Internal Crossflow written by John W. McClintic and published by . This book was released on 2017 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Film cooling is an essential technology to the operation of modern gas turbine engines, allowing for greater efficiency and part durability. Due to film cooling’s complexity, laboratory studies of film cooling isolate various effects by intentionally simplifying or neglecting various aspects of the film cooling problem. One such aspect that had been consistently neglected by film cooling studies is how the internal flow within the turbine blade affects film cooling performance. Studies have found that feeding the holes with an internal crossflow, directed perpendicular to the mainstream flow, can cause up to a 50% reduction in film cooling effectiveness. This result is of concern because internal crossflow is a common internal flow condition in gas turbine engines. However, none of the former studies have made a concerted effort to examine the important scaling parameters governing this effect. Nor have they provided experimental evidence showing the cause of this reduction in effectiveness due to internal crossflow. In this study, a wide range of flow conditions was studied for two common film cooling hole geometry types: axial and compound angle diffused-exit film cooling holes. Internal crossflow-to-mainstream velocity ratios of VR [subscript c] = 0.2-0.6 were tested along with jet-to-mainstream velocity ratios of VR = 0.2-1.7. Film cooling effectiveness and discharge coefficients were measured for this full range of flow conditions for both geometries in order to produce a sufficiently large data set to observe important trends in the data. It was found that the discharge coefficients, centerline effectiveness, and centerline location all scaled with the crossflow-to-jet velocity ratio, VR [subscript i] for the axial holes. Temperature and velocity fields showed that VR [subscript i] also scaled the in-hole temperature and velocity fields. A swirling flow within the hole was shown to cause ingestion of mainstream into the diffused exit of the hole and biasing of the issuing jet in the outlet diffuser, which reduced film cooling effectiveness. The direction of bias at the exit resulted from the direction of the internal crossflow and was critical for compound angle holes. Crossflow directed counter to the lateral direction of coolant injection caused improved film cooling effectiveness relative to the in-line crossflow direction
Download or read book 3D Velocity and Scalar Field Measurements of Discrete Hole Film Cooling Flows written by Emin Issakhanian and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Three-dimensional mean velocity field measurements from magnetic resonance velocimetry (MRV) are used to study the flow fields in the interaction region between the film cooling jet and the mainflow, as well as inside the film cooling hole, for different film cooling hole inclination angles and velocity ratios. The vorticity field created by the interaction of the in-hole vorticity and surface boundary layer vorticity is discovered to resemble a streamwise series of horseshoe vortices inclined in the forward direction. A streamwise-normal view of this field reveals the traditionally identified counter-rotating vortex pair (CVP) which is detrimental to film cooling. The in-hole flow feature of a counter-rotating vortex pair, which affects the main flow field, is also identified for inclined film cooling holes. Tracking of the coolant exiting the film cooling hole is achieved through 3D measurement of the coolant concentration in the mainflow using magnetic resonance concentration (MRC). Through the scalar analogy, concentration measurements are related to temperatures and the adiabatic surface effectiveness of the tested film cooling cases is measured. Shallower inclination angles and low velocity ratio jets are seen to produce coolant jets which remain closer to the surface and provide good film cooling. However, low velocity ratios correspond to low coolant flux which limits cooling performance due to high turbulent mixing. It is desirable to produce a film cooling hole which creates similarly advantageous flow fields at higher velocity ratios which increase coolant flux and endure more mixing before falling below effective cooling levels. This is attempted through shaped holes. MRV studies of three traditionally shaped film cooling holes, which diffuse laterally and/or in the forward direction over a final length of the hole, are done to evaluate the flowfield developed by different diffusion angles and diffusive section lengths. Increased exit area is seen to reduce the momentum of the exiting jet and produce coolant flows which remain closer to the surface. However, in-hole measurements of the two more conservative diffuser-shaped holes show uneven flow through the diffusing section of the hole and room for improvement. The most extreme diffuser-shaped hole shows marked decrease in the strength of the mainfield CVP. In addition to conventional film cooling holes, MRV is done on novel hole shapes to ascertain whether they will perform well as film cooling holes. A round hole which lofts into an exit section modeled on two intersecting yawed holes is studied, which creates a pair of CVPs which lead to central vortices spinning counter to a conventional CVP. Two non-circular cross-section holes, a spanwise-stretched oval and a rounded triangle pointing streamwise, are tested in hopes of decreasing streamwise vorticity in the mainflow. The rounded triangle shapes leads to a very lifted coolant jet and increased vorticity, but the oval shape creates a coolant jet with a more complex vorticity field which remains attached and creates a beneficial velocity profile along the surface. MRC was done on the oval shaped hole, because of the promising flow features observed in the MRV results. Comparison of the surface effectiveness to all round hole cases and a single diffuser-shaped hole case show marked improvement in film cooling using an oval shaped hole over traditional round and diffuser-shaped holes.
Download or read book Proceedings written by and published by . This book was released on 1987 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt:
