Experimental study on frosting/defrosting characteristics of microgrooved metal surfaces

Abstract Effect of microgroove geometry on the frost formation and frost melt-water drainage is experimentally investigated on a number of aluminum surfaces. Condensation and frost formation processes are also examined on a set of microgrooved copper surfaces for which the dimensions of the microgroove geometry are varied in a cyclic manner. These metal surfaces are studied because of their technical importance as working materials and are fabricated by two different techniques, photolithography and wet etching, respectively. The morphology, distribution and growth pattern of the condensed and frozen water droplets are found to be considerably different on the microgrooved surfaces from that on the flat baseline surfaces. While the amount of frost melt-water retention on the flat surfaces is found to increase in the subsequent refrost cycles and is highest in the last frost cycle, the microgrooved aluminum surfaces consistently exhibit improved frost-water drainage in all frost cycles and under different operating conditions. Findings of this study will be useful in designing microgrooved metal surfaces operating under frosting/defrosting conditions to have improved frost-water drainage properties.

[1]  Wenjin Wang,et al.  Investigation of defrosting water retention on the surface of evaporator impacting the performance of air source heat pump during periodic frosting–defrosting cycles , 2014 .

[2]  D. Beysens,et al.  Nucleation and growth on a superhydrophobic grooved surface. , 2004, Physical review letters.

[3]  A. V. Tikhonov,et al.  Experimental Study on Frost Structure on Surfaces With Different Hydrophilicity: Density and Thermal Conductivity , 2003 .

[4]  R. Webb,et al.  Condensate formation and drainage on typical fin materials , 2001 .

[5]  Woo-Seung Kim,et al.  Effect of surface treatments on the frosting/defrosting behavior of a fin-tube heat exchanger , 2002 .

[6]  Md. Ashiqur Rahman,et al.  Condensation, Frost Formation, and Frost Melt-Water Retention Characteristics on Microgrooved Brass Surfaces Under Natural Convection , 2013 .

[7]  Neelesh A Patankar,et al.  Anisotropy in the wetting of rough surfaces. , 2005, Journal of colloid and interface science.

[8]  Zhongliang Liu,et al.  Frost formation on a super-hydrophobic surface under natural convection conditions , 2008 .

[9]  Lorenzo Cremaschi,et al.  Experimental measurements of the surface coating and water retention effects on frosting performance of microchannel heat exchangers for heat pump systems , 2012 .

[10]  A. Jacobi,et al.  Issues affecting the reliability of dynamic dip testing as a method to assess the condensate drainage behavior from the air-side surface of dehumidifying heat exchangers , 2008 .

[11]  J. Ding,et al.  Water condensation on superhydrophobic aluminum surfaces with different low-surface-energy coatings , 2012 .

[12]  J. Georgiadis,et al.  Effects of surface chemistry and groove geometry on wetting characteristics and droplet motion of water condensate on surfaces with rectangular microgrooves , 2013 .

[13]  R. Yu,et al.  Condensate drainage performance of a plain fin-and-tube heat exchanger constructed from anisotropic micro-grooved fins , 2012 .

[14]  Anthony M. Jacobi,et al.  Dynamic dip testing as a method to assess the condensate drainage behavior from the air-side surface of compact heat exchangers , 2005 .

[15]  Kazuhito Hashimoto,et al.  Effects of Surface Structure on the Hydrophobicity and Sliding Behavior of Water Droplets , 2002 .

[16]  Shuhuai Yao,et al.  Factors affecting the spontaneous motion of condensate drops on superhydrophobic copper surfaces. , 2012, Langmuir : the ACS journal of surfaces and colloids.

[17]  Evelyn N Wang,et al.  Condensation on superhydrophobic surfaces: the role of local energy barriers and structure length scale. , 2012, Langmuir : the ACS journal of surfaces and colloids.

[18]  Sam-Chul Ha,et al.  Frost formation on a plate with different surface hydrophilicity , 2004 .

[19]  A. Jacobi,et al.  Condensate Retention Effects on the Performance of Plain-Fin-and-Tube Heat Exchangers: Retention Data and Modeling , 2001 .

[20]  Anthony M. Jacobi,et al.  Creating micro-scale surface topology to achieve anisotropic wettability on an aluminum surface , 2006 .

[21]  A. Sommers,et al.  Predicting the onset of condensate droplet departure from a vertical surface due to air flow—Applications to topographically-modified, micro-grooved surfaces , 2012 .

[22]  A. Jacobi,et al.  Air-Side Surface Wettability Effects on the Performance of Slit-Fin-and-Tube Heat Exchangers Operating Under Wet-Surface Conditions , 2009 .

[23]  Predrag Stojan Hrnjak,et al.  Frost, defrost, and refrost and its impact on the air-side thermal-hydraulic performance of louvered-fin, flat-tube heat exchangers , 2006 .

[24]  G. Ross,et al.  Experimental Study on the Evolution of Contact Angles with Temperature Near the Freezing Point , 2010 .

[25]  T. Deng,et al.  Frost formation and ice adhesion on superhydrophobic surfaces , 2010 .

[26]  A. Nakajima,et al.  Effect of dew condensation on the wettability of rough hydrophobic surfaces coated with two different silanes. , 2010, Langmuir : the ACS journal of surfaces and colloids.

[27]  Anthony M. Jacobi,et al.  Study of frost properties and frost melt water drainage on microgrooved brass surfaces in multiple frost/defrost/refrost cycles , 2014 .

[28]  A. Jacobi,et al.  A surface embossing technique to create micro-grooves on an aluminum fin stock for drainage enhancement , 2009 .

[29]  Anthony M. Jacobi,et al.  Effect of Substrate Wettability on Frost Properties , 2004 .

[30]  Konrad Rykaczewski,et al.  Microdroplet growth mechanism during water condensation on superhydrophobic surfaces. , 2012, Langmuir : the ACS journal of surfaces and colloids.

[31]  Md. Ashiqur Rahman,et al.  Effects of microgroove geometry on the early stages of frost formation and frost properties , 2013 .

[32]  H. Otsuka,et al.  Macroscopic-wetting anisotropy on the line-patterned surface of fluoroalkylsilane monolayers. , 2005, Langmuir : the ACS journal of surfaces and colloids.

[33]  J. Georgiadis,et al.  Freezing Front Propagation on Microgrooved Substrates , 2010 .

[34]  Anthony M. Jacobi,et al.  Drainage of frost melt water from vertical brass surfaces with parallel microgrooves , 2012 .