Experimental Study of an Impingement Cooling-Jet Array Using an Infrared Thermography Technique

2012 ◽  
Vol 26 (4) ◽  
pp. 590-597 ◽  
Author(s):  
Andrew Schroder ◽  
Shichuan Ou ◽  
Urmila Ghia
Keyword(s):  
Experimental Study ◽  
Infrared Thermography ◽  
Impingement Cooling ◽  
Jet Array

Experimental Study on Racetrack-Shaped Holes Impingement Cooling With Bump Type Roughening Element

2012 ◽  
Author(s):  
Chiyuki Nakamata ◽  
Yoji Okita ◽  
Takashi Yamane ◽  
Yoshitaka Fukuyama ◽  
Toyoaki Yoshida
Keyword(s):  
Experimental Study ◽  
Flow Condition ◽  
Reynolds Numbers ◽  
Main Flow ◽  
The Other ◽  
Relative Location ◽  
Target Plate ◽  
Cooling Effectiveness ◽  
Impingement Cooling ◽  
Cooling Air

Cooling effectiveness of an impingement cooling with array of racetrack-shaped impingement holes is investigated. Two types of specimens are investigated. One is a plain target plate and the other is a plate roughened with bump type elements. Sensitivity of relative location of bump to impingement hole on the cooling effectiveness is also investigated. Experiments are conducted under three different mainflow Reynolds numbers ranging from 2.6×105 to 4.7×105, with four different cooling air Reynolds numbers for each main flow condition. The cooling air Reynolds numbers are in the range from 1.2×103 to 1.3×104.

Thermal Performance of Micro-Jet Impingement Device With Parallel Flow, Jet-Adjacent Fluid Removal

2018 ◽  
Author(s):  
Todd M. Bandhauer ◽  
David R. Hobby ◽  
Chris Jacobsen ◽  
Dave Sherrer
Keyword(s):  
Reynolds Number ◽  
Thermal Resistance ◽  
Thermal Performance ◽  
Heated Surface ◽  
Jet Impingement ◽  
Impinging Jets ◽  
Thermal Interface Material ◽  
Cooling Device ◽  
Impingement Cooling ◽  
Jet Array

In a variety of electronic systems, cooling of various components imposes a significant challenge. A major aspect that inhibits the performance of many cooling solutions is the thermal resistance between the chip package and the cooling structure. Due to its low thermal conductivity, the thermal interface material (TIM) layer imposes a significant thermal resistance on the chip to cooling fluid thermal path. Advanced cooling methods that bypass the TIM have shown great potential in research and some specialty applications, yet have not been adopted widely by industry due to challenges associated with practical implementation and economic constraints. One advanced cooling method that can bypass the TIM is jet impingement. The impingement cooling device investigated in the current study is external to the integrated circuit (IC) package and could be easily retrofitted onto any existing microchip, similar to a standard heatsink. Jet impingement cooling has proven effective in previous studies. However, it has been shown that jet-to-jet interference severely degrades thermal performance of an impinging jet array. The present research addresses this challenge by utilizing a flow path geometry that allows for withdrawal of the impinging fluid immediately adjacent to each jet in the array. In this study, a jet impingement cooling solution for high-performance ICs was developed and tested. The cooling device was fabricated using modern advanced manufacturing techniques and consisted of an array of micro-scale impinging jets. A second array of fluid return paths was overlain across the jet array to allow for direct fluid extraction in the immediate vicinity of each jet, and fluid return passages were oriented in parallel to the impinging jets. The following key geometric parameters were utilized in the device: jet diameter (D = 300μm), distance from jet to impinging surface (H/D = 2.5), spacing between jets (S/D = 8), spacing between fluid returns (Sr/D = 8), diameter of fluid returns (Dr/D = 5). The device was mounted to a 2cm × 2cm uniformly heated surface which produced up to 165W and the resulting fluid-to-surface temperature difference was measured at a variety of flow rates. For this study, the device was tested using single-phase water. Jet Reynolds number ranged from 300–1500 and an average heat transfer coefficient of 13,100 W m−2 K−1 was achieved at a Reynolds number of only Red = 305.

Theoretical and Experimental Study on Nondestructive Pulse Phase Infrared Thermography Testing Technology

2011 ◽  
Vol 314-316 ◽  
pp. 1483-1486
Author(s):  
Qing Ju Tang ◽  
Jun Yan Liu ◽  
Yang Wang
Keyword(s):  
Experimental Study ◽  
Infrared Thermography ◽  
Testing Effect ◽  
Experimental Results ◽  
Composite Specimen ◽  
Experimental Platform ◽  
Phase Images ◽  
Testing Technology ◽  
Pulsed Phase Thermography ◽  
Non Destructive

The non-destructive pulsed phase thermography technique was used to detect metal specimen with flat blind-bottom holes and composite specimen with sticky areas. An experimental platform was built base on the analysis of the pulsed phase thermography testing principle. Experimental results show the different testing effect of the original thermography, amplitude and phase images.

Experimental Study of the Flow and Thermal Development of a Row of Cooling Jets Impinging on a Rotating Concave Surface

2004 ◽  
Author(s):  
Hector Iacovides ◽  
Diamantis Kounadis ◽  
Brian E. Launder ◽  
Jiankang Li ◽  
Zeyuan Xu
Keyword(s):  
Experimental Study ◽  
Nusselt Number ◽  
Thermal Behavior ◽  
Spreading Rate ◽  
Concave Surface ◽  
Cooling Fluid ◽  
Impingement Cooling ◽  
Axis Parallel ◽  
Stationary Conditions ◽  
Cooling Passage

The paper reports an experimental study of impingement cooling in a rotating passage of semi-cylindrical cross-section. Cooling fluid is injected from a row of five jet holes along the centerline of the flat surface of the passage and strikes the concave surface. The cooling passage rotates orthogonally about an axis parallel to that of the jets. Tests have been carried out, using water, both within the passage and as the jet fluid, at a fixed Reynolds number of 15,000, for clockwise and anti-clockwise rotation. Local Nusselt number measurements, using the liquid-crystal technique, show that under stationary conditions a high Nusselt number region develops around each impingement point, with secondary peaks half-way between impingement points. Rotation reduces heat transfer, leads to the disappearance of all secondary peaks and also, surprisingly, of some of the primary peaks. Flow visualization tests suggest that these changes in thermal behavior are caused because rotation increase the spreading rate of the jets. LDA and PIV measurements are also presented. They show that under stationary conditions the five jets exhibit a similar behavior, with their cores remaining intact up to the point of impingement at the top dead center. The LDA and PIV studies help explain the rather surprising thermal behavior under rotating conditions.

Experimental Study of the Flow and Thermal Development of a Row of Cooling Jets Impinging on a Rotating Concave Surface

2005 ◽  
Vol 127 (1) ◽  
pp. 222-229 ◽  
Author(s):  
Hector Iacovides ◽  
Diamantis Kounadis ◽  
Brian E. Launder ◽  
Jiankang Li ◽  
Zeyuan Xu
Keyword(s):  
Experimental Study ◽  
Nusselt Number ◽  
Thermal Behavior ◽  
Spreading Rate ◽  
Concave Surface ◽  
Cooling Fluid ◽  
Impingement Cooling ◽  
Axis Parallel ◽  
Stationary Conditions ◽  
Cooling Passage

The paper reports an experimental study of impingement cooling in a rotating passage of semi-cylindrical cross section. Cooling fluid is injected from a row of five jet holes along the centerline of the flat surface of the passage and strikes the concave surface. The cooling passage rotates orthogonally about an axis parallel to that of the jets. Tests have been carried out, using water, both within the passage and as the jet fluid, at a fixed Reynolds number of 15,000, for clockwise and counter-clockwise rotation. Local Nusselt number measurements, using the liquid-crystal technique, show that under stationary conditions a high Nusselt number region develops around each impingement point, with secondary peaks half-way between impingement points. Rotation reduces heat transfer, leads to the disappearance of all secondary peaks and also, surprisingly, of some of the primary peaks. Flow visualization tests suggest that these changes in thermal behavior are caused because rotation increases the spreading rate of the jets. LDA and PIV measurements are also presented. They show that under stationary conditions the five jets exhibit a similar behavior, with their cores remaining intact up to the point of impingement at the top dead center. The LDA and PIV studies help explain the rather surprising thermal behavior under rotating conditions.

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