Author: Yuming ZhangPublisher:
ISBN:
Category :
Languages : en
Pages : 144
Book Description
Jet Impingement Heat Transfer in Two-pass Rotating Rectangular Channels
Author: Yuming ZhangRotation Effect on Jet Impingement Heat Transfer in Smooth Rectangular Channels with Four Heated Walls and Radially Outward Cross Flow
Author: J. A. ParsonsPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Presented at the International Gas Turbine and Aeroengine Congress & Exhibition, Birmingham, UK, Jun 10-13, 1996.
Gas Turbine Heat Transfer and Cooling Technology
Author: Je-Chin HanPublisher: Taylor & Francis
ISBN: 1466564903
Category : Science
Languages : en
Pages : 865
Book Description
A comprehensive reference for engineers and researchers, this second edition focuses on gas turbine heat transfer issues and their associated cooling technologies for aircraft and land-based gas turbines. It provides information on state-of-the-art cooling technologies such as advanced turbine blade film cooling and internal cooling schemes. The book also offers updated experimental methods for gas turbine heat transfer and cooling research, as well as advanced computational models for gas turbine heat transfer and cooling performance predictions. The authors provide suggestions for future research within this technology and includes 800 illustrations to help clarify concepts and instruction.
Aspect Ratio Effect on Heat Transfer in Rotating Two-pass Rectangular Channels with Smooth Walls and Ribbed Walls
Author: Wen-Lung FuPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
This study experimentally investigates the effects of rotation, the buoyancy force, and the channel aspect ratio on heat transfer in two-pass rotating rectangular channels. The experiments are conducted with two surface conditions: smooth walls and 45° angled ribbed walls. The channel aspect ratios include 4:1, 2:1, 1:1, 1:2 and 1:4. Four Reynolds numbers are studied: 5000, 10000, 25000 and 40000. The rotation speed is fixed at 550 rpm for all tests, and for each channel, two channel orientations are studied: 90° and 45° or 135°, with respect to the plane of rotation. Rib turbulators are placed on the leading and trailing walls of the channels at an angle of 45° to the flow direction. The ribs have a 1.59 by 1.59 mm square cross section, and the rib pitch-to-height ratio (P/e)is 10 for all tests. The effects of the local buoyancy parameter and channel aspect ratio on the regional Nusselt number ratio are presented. Pressure drop data are also measured for both smooth and ribbed channels in rotating and non-rotating conditions. The results show that increasing the local buoyancy parameter increases the Nusselt number ratio on the trailing surface and decreases the Nusselt number ratio on the leading surface in the first pass for all channels. However, the trend of the Nusselt number ratio in the second pass is more complicated due to the strong effect of the 180° turn. Results are also presented for this critical turn region of the two-pass channels. In addition to these regions, the channel averaged heat transfer, friction factor, and thermal performance are determined for each channel. With the channels having comparable Nusselt number ratios, the 1:4 channel has the superior thermal performance because it incurs the least pressure penalty. In this study, the author is able to systematically analyze, correlate, and conclude the thermal performance comparison with the combination of rotation effectson five different aspect ratio channels with both smooth walls and rib turbulated walls.
Introduction to Enhanced Heat Transfer
Author: Sujoy Kumar SahaPublisher: Springer
ISBN: 3030207404
Category : Science
Languages : en
Pages : 103
Book Description
This Brief stands as a primer for heat transfer fundamentals in heat transfer enhancement devices, the definition of heat transfer area, passive and active enhancement techniques and their potential and benefits and commercial applications. It further examines techniques and modes of heat transfer like single-phase flow and two-phase flow, natural and forced convection, radiation heat transfer and convective mass transfer.
Heat Transfer in Smooth and Ribbed Rectangular Two-pass Channels with a Developing Flow Entrance at High Rotation Numbers
Author: Michael HuhPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Cooling channels with a developing flow entrance condition and aspect ratios of 1:4 and 2:1 were studied. The range of the rotation number and buoyancy parameter for the selected AR channels was extended. The maximum Ro and Bo for the 1:4 channel was 0.67 and 1.9, respectively. For the 2:1 channel, these values were 0.45 and 0.85, respectively. The effect of rib spacing and rib height on heat transfer in the 1:4 channel is investigated. Three rib spacing configurations were considered: P/e=2.5, 5, 10 with a constant e/Dh ratio of 0.078. To investigate the effect of rib height, a rib configuration with an e/Dh ratio of 0.156 and P/e ratio of 10 was considered. For the 2:1 channel, a smooth channel surface condition was studied. For each channel aspect ratio and surface condition, five Reynolds numbers were studied up to 40K. At each Re, five rotational speeds are considered up to 400 rpm. The results of this research work indicate that rotation can cause a significant increase in heat transfer on the first pass trailing surface of both aspect ratio channels. The leading surface in ribbed channels has shown a dramatic decrease in heat transfer with rotation in the first pass. Reductions in heat transfer by as much as 50% were observed. In the second pass, the leading and trailing surfaces with ribs showed very similar effects of rotation. Also, the effect of rotation seems to vary with the rib spacing. The strength of rotation showed to be greater in the tight rib spacing of P/e=2.5. The rib height in the 1:4 channel had minimal impact due to the large distance between the leading and trailing surfaces. The tip cap heat transfer for both channels showed large increases with rotation. This is very beneficial since tip cooling is an important part of maintaining the life a turbine blade. Finally, the buoyancy parameter proved to be very useful in predicting heat transfer in rotating conditions. The correlations developed showed very acceptable accuracy when compared to the experimental data.
Journal of Thermophysics and Heat Transfer
Author: Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 996
Book Description
This journal is devoted to the advancement of the science and technology of thermophysics and heat transfer through the dissemination of original research papers disclosing new technical knowledge and exploratory developments and applications based on new knowledge. It publishes papers that deal with the properties and mechanisms involved in thermal energy transfer and storage in gases, liquids, and solids or combinations thereof. These studies include conductive, convective, and radiative modes alone or in combination and the effects of the environment.
Jet Impingement Heat Transfer Over Rotating Surfaces
Author: Pratik Santosh BhansaliPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Introduction to Heat Transfer
Author: Bengt SundénPublisher: WIT Press
ISBN: 1845646568
Category : Science
Languages : en
Pages : 365
Book Description
Presenting the basic mechanisms for transfer of heat, this book gives a deeper and more comprehensive view than existing titles on the subject. Derivation and presentation of analytical and empirical methods are provided for calculation of heat transfer rates and temperature fields as well as pressure drop. The book covers thermal conduction, forced and natural laminar and turbulent convective heat transfer, thermal radiation including participating media, condensation, evaporation and heat exchangers. This book is aimed to be used in both undergraduate and graduate courses in heat transfer and thermal engineering. It can successfully be used in R & D work and thermal engineering design in industry and by consultancy firms
Author: Srivatsan Madhavan