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This experimental study investigates condensation on micro-grooved plates to optimize surface tension effects, vapor shear, and gravitational forces. The study focuses on condensate removal, thin film retention, and capillary pumping enhancement in micro heat pipes. Results show the micro grooves improve condensation heat transfer coefficients, with larger grooves showing better performance. Further research is recommended to enhance the efficiency of micro grooves.
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Experimental Study of Condensation on Micro Grooved Plates R. Barron-jimenez, H. Y. Hu, G. P. Peterson Department of Mechanical Engineering Texas A&M University
Overview • Introduction • Experimental System • Apparatus • Test Plates • Test Conditions • Results • Overall Condensation Heat Transfer Coefficient • Condensate Removal • Conclusions
Scientific Interest Optimum geometry to take advantage of the surface tension Effect of vapor shear during condensation Role of gravitational body force during condensation Applications Condensate removal Thin film Retain liquid Enhance capillary pumping in micro heat pipes Micro Grooves Better understanding of the condensation phenomena
Test Plates Micro Grooves Geometry
Test Conditions • Vapor velocity : 4.14±0.64 m/s • Re (transition regime) : 3.474*103 • System pressure : 101.35 kPa • Plate orientation : Horizontal • Cooling Temperature : 20, 35, 50, or 65ºC
Test Conditions Constant Plate Temperature Assumption
Results Overall Condensation Heat Transfer Coefficient Plate 5 vs. 3 (W) : 1.75 and 2.9 times larger q = 60º vs. 45º : 1.55 better
Results Overall Condensation Heat Transfer Coefficient Average Uh: 52%
Results Condensate Removal Micro grooves in plate 5 are better than smooth surface
Conclusions • Data is not conclusive. Further work is recommended • Large micro grooves with 60º apex angles tend to work better (best performance: Plate 5) • Tests conditions improve the micro grooves performance • Micro grooves help to maintain a stable condensation pattern • Eliminate “wall channel” effect and reduce heat losses
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