scholarly journals Bluff Body Impact on Harvested Heat Transfer from Heated Plate

2021 ◽  
Vol 171 (0) ◽  
pp. 166-178
Author(s):  
Osama khoraisa ◽  
Mohamed Abdullaha ◽  
Kareem Emara
Keyword(s):  
Heat Transfer ◽  
Bluff Body ◽  
Heated Plate

An Experimental Investigation of Heat Transfer and Buoyancy Induced Transition from Laminar Forced Convection to Turbulent Free Convection over a Horizontal Isothermally Heated Plate

1978 ◽  
Vol 100 (3) ◽  
pp. 429-434 ◽  
Author(s):  
H. Imura ◽  
R. R. Gilpin ◽  
K. C. Cheng
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Forced Convection ◽  
Leading Edge ◽  
Finite Amplitude ◽  
Heated Plate ◽  
Transfer Rates ◽  
Longitudinal Vortices ◽  
Turbulent Flow Regime ◽  
Laminar Forced Convection

The flow over a horizontal isothermally heated plate at Reynolds numbers below that at which hydrodynamic instabilities exist, is characterized by a region of laminar forced convection near the leading edge, followed by the onset of longitudinal vortices and their growth to a finite amplitude and finally a transition to a turbulent flow regime. Results are presented for the temperature profiles, the thermal boundary layer thickness, and the local Nusselt number. They are used to identify the various flow regimes. It was found that the transition from laminar forced convection to turbulent convection was characterized by the parameter Grx/Rex1.5 falling in the range 100 to 300. For values of this parameter greater than 300 the heat transfer rates were independent of Reynolds number and typical of those for turbulent free convection from a horizontal surface.

Thermo-mechanical analysis of a FGM plate subjected to thermal shock – A new numerical approach considering real time temperature dependent material properties

2021 ◽  
Vol 63 (4) ◽  
pp. 341-349
Author(s):  
Mete Onur Kaman ◽  
Nevin Celik ◽  
Resul Das
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Thermal Shock ◽  
Temperature Variation ◽  
Material Properties ◽  
Ambient Air ◽  
Transient Temperature ◽  
Heated Plate ◽  
The Heat Transfer Coefficient

Abstract In present the study, sudden cooling, in other words thermal shock, is applied to a plate that is originally a functionally graded material (FGM). The flat plate is assumed to have an edge crack on it. Hence a numerical couple-field analysis is performed on the plate. The FGM is a combination of Ni and Al2O3. The thermal and mechanical properties of the FGM are assumed to depend on temperature variation. The mixing percentages of the Ni and Al2O3 throughout the plate are considered to vary (i) linearly, (ii) quadratically and (iii) in half-order. In order to solve the problem, a new subroutine depending on temperature is written using APDL (ANSYS Parametric Design Language) codes. Three values of the heat transfer coefficient are applied to the initially heated plate. As a result, the transient temperature variation and stress intensity factor are presented to show the thermo-mechanical relation of the plate. The material properties changing with temperature results in more reliable temperature values. Increasing the heat transfer coefficient results in better cooling and in a lesser amount of time to reach ambient air temperature.

scholarly journals Heat Transfer in the Core Compressor Under Ice Crystal Icing Conditions

2017 ◽  
Author(s):  
Alexander Bucknell ◽  
Matthew McGilvray ◽  
David R. H. Gillespie ◽  
Geoff Jones ◽  
Alasdair Reed ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Particle Diameter ◽  
Energy Parameter ◽  
National Research Council ◽  
Heated Plate ◽  
Ice Crystal ◽  
Transfer Enhancement ◽  
The Core ◽  
Ice Particles

It has been recognised in recent years that high altitude atmospheric ice crystals pose a threat to aircraft engines. Instances of damage, surge and shutdown have been recorded at altitudes significantly greater than those associated with supercooled water icing. It is believed that solid ice particles can accrete inside the core compressor, although the exact mechanism by which this occurs remains poorly understood. Development of analytical and empirical models of the ice crystal icing phenomenon is necessary for both future engine design and this-generation engine certification. A comprehensive model will require the integration of a number of aerodynamic, thermodynamic and mechanical components. This paper studies one such component, specifically the thermodynamic and mechanical processes experienced by ice particles impinging on a warm surface. Results are presented from an experimental campaign using a heated and instrumented flat plate. The plate was installed in the Altitude Icing Wind Tunnel (AIWT) at the National Research Council of Canada (NRC). This facility is capable of replicating ice crystal conditions at altitudes up to 9 km and Mach numbers up to 0.55 [1]. The heated plate is designed to measure the heat flux from a surface at temperatures representative of the early core compressor, under varying convective and icing heat loads. Heat transfer enhancement was observed to rise approximately linearly with both total water content and particle diameter over the ranges tested. A Stokes number greater than unity proved to be a useful parameter in determining whether heat transfer enhancement would occur. A particle energy parameter was used to estimate the likelihood of fragmentation. Results showed that when particles were both ballistic and likely to fragment, heat transfer enhancement was independent of both Mach and Reynolds numbers over the ranges tested.

Experiments on Fluid Flow and Heat Transfer in a Packed Channel Between Two Parallel Grooved Plates

2001 ◽  
Author(s):  
J. H. Du ◽  
B. Ma ◽  
W. Wu ◽  
X. J. Hu ◽  
B. X. Wang
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Flow Resistance ◽  
Direct Consequence ◽  
Contact Condition ◽  
Heated Plate ◽  
Flow And Heat Transfer ◽  
Performance Of Heat Transfer ◽  
Specific Configuration ◽  
Film Heat Transfer

Abstract Experiments on fluid flow and heat transfer in a glass bead packed channel between two parallel grooved plates were conducted. The effects of the grooves on the surface of the heated plate upon the flow resistance and heat transfer were investigated. The results indicated that the grooves on the plate surface change the contact condition of the packed beads to the wall and increase the wall effect of the packed channels. Its direct consequence is to lower the flow resistance. The film heat transfer coefficient on the wall may be increased or rebated. It is demonstrated that a proper combination of packed beads and grooves can lead to the optimum performance of heat transfer for a specific configuration.

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