CROSS FLOW INFLUENCE UPON IMPINGEMENT CONVECTIVE HEAT TRANSFER IN CIRCULAR ARRAYS OF JETS : A GENERAL CORRELATION

1982 ◽  
Author(s):  
S. Galant ◽  
G. Martinez
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Cross Flow ◽  
General Correlation ◽  
Circular Arrays

scholarly journals Conjugate Heat Transfer CFD Predictions of Impingement Jet Array Flat Wall Cooling Aerodynamics With Single Sided Flow Exit

2013 ◽  
Author(s):  
Abubakar M. El-Jummah ◽  
Gordon E. Andrews ◽  
John E. J. Staggs
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Conjugate Heat Transfer ◽  
Cross Flow ◽  
Diameter Ratio ◽  
Significant Feature ◽  
Axial Distance ◽  
Impingement Jet ◽  
The Cross

Conjugate heat transfer CFD studies were undertaken on impingement square jet arrays with self induced crossflow in the impingement gap with a single sided exit. The aim was to understand the aerodynamic interactions that result in the deterioration of heat transfer with axial distance, whereas the addition of duct flow heat transfer would be expected to lead to an increase in heat transfer with axial distance. A square array of impingement holes was investigated for a common geometry investigated experimentally, pitch to diameter ratio X/D of 5 and impingement gap to diameter ratio Z/D of 3.3 for 11 rows of holes in the crossflow direction. A metal duct wall was used as the impingement surface with an applied heat flux of 100kW/m2, which for a gas turbine combustor cooling application operating at steady state with a temperature difference of ∼450K corresponds to a convective heat transfer coefficient of ∼200 W/m2K. A key feature of the predicted aerodynamics was recirculation in the plane of the impingement jets normal to the cross-flow, which produced heating of the impingement jet wall. This reverse flow jet was deflected by the cross flow which had its peak velocity in the plane between the high velocity impingement jets. The cross-flow interaction with the impingement jets reduced the interaction between the jets on the surface, with lower surface turbulence as a result and this reduced the surface convective heat transfer. A significant feature of the predictions was the interaction of the cross-flow aerodynamics with the impingement jet wall and associated heat transfer to that wall. The results showed that the deterioration in heat transfer with axial distance was well predicted, together with predictions of the impingement wall surface temperature gradients.

Calculation of Convective Heat Transfer of Plane Surfaces with Wire-Net Finning Immersed in a Cross-Flow

2005 ◽  
Vol 36 (1-2) ◽  
pp. 39-46 ◽  
Author(s):  
E. N. Pis'mennyi ◽  
A. M. Terekh ◽  
V. A. Rogachev ◽  
V. D. Burlei ◽  
A. I. Rudenko
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Cross Flow

Experimental Investigation of Dynamically Forced Impingement Cooling

2017 ◽  
Author(s):  
Arne Berthold ◽  
Frank Haucke
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Cross Flow ◽  
Side Wall ◽  
Cooling Efficiency ◽  
Liquid Crystal Thermography ◽  
Nusselt Numbers ◽  
Dynamic Forcing ◽  
The Individual

The influence of dynamic forcing of a 7 by 7 impinging jet array on the cooling efficiency is investigated experimentally. Thereby, this work focused on determining the influence side wall induced cross flow has on the local convective heat transfer on an electrically heated target plate and on enhancing the local convective heat transfer. For the enhancement the main focus is on the influence of the impingement distance, the impingement frequency and the phaseshift between the individual rows of nozzles. Liquid crystal thermography is employed for measuring the local wall temperatures, which are used to calculate the local Nusselt numbers. The cooling efficiency of this dynamic approach is determined by comparing local Nusselt numbers with steady blowing conditions.

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