Citations Only: Recent submissions
Now showing items 261-280 of 990
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Effect of channel roughness on heat transfer and fluid flow characteristics at low Reynolds numbers in small diameter tubes
(American Society of Mechanical Engineers (ASME), 2001-06)The effect of roughness on pressure drop and heat transfer in circular tubes has been extensively studied in literature. The pioneering work of Nikuradse (1933) established the sand grain roughness as a major parameter ... -
Fundamental issues related to flow boiling in minichannels and microchannels
(Elsevier, 2002-09)Flow boiling in small hydraulic diameter channels is becoming increasingly important in many diverse applications. The previous studies addressing the effects of the channel size on the flow patterns, and heat transfer ... -
High-Speed photographic observation of flow boiling of water in parallel mini-channels
(American Society of Mechanical Engineers (ASME), 2001-06)The use of smaller passage dimensions is becoming more prevalent in flow boiling applications. Passages with hydraulic diameters on the order of 1mm provide higher heat transfer coefficients resulting in more compact ... -
Effects of Weber number and surface temperature on the boiling and spreading characteristics of impinging water droplets
(American Society of Mechanical Engineers (ASME), 2002-06)In the present work, the effects of Weber number and surface temperature upon the droplet impingement behavior and boiling characteristics have been experimentally studied. High speed photography (up to 8000 frames per ... -
Evolution of microchannel flow passages – Thermohydraulic performance and fabrication technology
(Taylor & Francis, 2003)This paper provides a roadmap of development in the thermal and fabrication aspects of microchannels as applied in microelectronics and other high heat-flux cooling applications. Microchannels are defined as flow passages ... -
Effect of entrance condition on frictional losses and transition to turbulence
(American Society of Mechanical Engineers (ASME), 2002-11)In studying the fluid flow and heat transfer in microchannels, various claims have been made regarding transition at Reynolds numbers significantly below 2300. As a first step in identifying the reasons for such early ... -
Microchannels and minichannels - History, terminology, classification and current research needs
(American Society of Mechanical Engineers (ASME), 2003-04)Microchannels and Minichannels are found in many biological systems providing very high heat and mass transfer rates in organs such as the brain, lung, liver and kidney. Many high flux cooling applications are effectively ... -
Heat transfer mechanisms during flow boiling in microchannels
(American Society of Mechanical Engineers (ASME), 2003-04)The forces due to surface tension, inertia, and momentum change during evaporation in microchannel govern the two-phase flow patterns and the heat transfer characteristics during flow boiling. These forces are analyzed in ... -
Critical heat flux in microchannels: Experimental issues and guidelines for measurement
(American Society of Mechanical Engineers (ASME), 2003-04)Critical heat flux limit is an important consideration in the design of any flow boiling unit. Before the use of microchannels under flow boiling conditions becomes widely accepted in critical applications, such as electronics ... -
Extending the applicability of the flow boiling correlation to low Reynolds number flows in microchannels
(American Society of Mechanical Engineers (ASME), 2003-04)As microchannels are applied in flow boiling applications, it is becoming apparent that the Reynolds number based on all liquid flow could approach values below 100. The earlier work by Kandlikar and Steinke (2002, 2003) ... -
High speed photographic observation of flow patterns during flow boiling in single rectangular minichannel
(American Society of Mechanical Engineers (ASME), 2003-07)The present study extends the range of flow patterns observed during boiling of water in a single minichannel of height 197 mm and width 1054 mm. The calculated hydraulic diameter of the channel is 333 mm. High-speed ... -
Heat transfer from a moving and evaporating meniscus on a heated surface
(American Society of Mechanical Engineers (ASME), 2003-07)A stable meniscus is formed between a needle dispensing water over a heated circular face of a rotating copper block. The needle is offset from the axis of rotation and thus forms a moving meniscus. The water flow rate, ... -
Examples of microchannel mass transfer processes in biological systems
(American Society of Mechanical Engineers (ASME), 2003-04)Heat and mass transfer processes become highly efficient as the channel hydraulic diameter is reduced in size. Biological systems, such as human body, rely on the extremely efficient transport processes occurring at ... -
Transient thermal analysis of a microprocessor using a heat spreader with variable thermal storage characteristics
(American Society of Mechanical Engineers (ASME), 2002-04)The thermal performance of a heat spreader with Phase Change Material (PCM) is investigated experimentally under transient conditions. The transient thermal load generated by a microprocessor is obtained by running a ... -
Experimental study of flow patterns, pressure drop and flow instabilities in parallel rectangular minichannels
(American Society of Mechanical Engineers (ASME), 2004-06)The use of phase change heat transfer in parallel minichannels and microchannels is one of the solutions proposed for cooling high heat flux systems. The increase in pressure drop in a two phase system is one of the problems, ... -
Effect of entrance condition on frictional losses and transition to turbulence in minichannel flows
(American Society of Mechanical Engineers (ASME), 2004-06)In studying the fluid flow and heat transfer in microchannels and minichannels, various claims have been made regarding transition at Reynolds numbers significantly below 2300. As a first step in identifying the reasons ... -
Experimental study of heat transfer, pressure drop, and dryout for flow boiling of water in an oil heated minichannel
(American Society of Mechanical Engineers (ASME), 2004-06)Heat transfer and pressure drop, are experimentally recorded for flow boiling water in a single 706 mm circular copper channel 158.75 mm long. Heat is supplied by heat transfer oil at specified temperatures to a helical ... -
Optimization of microchannel geometry for direct chip cooling using single phase heat transfer
(American Society of Mechanical Engineers (ASME), 2004-06)Direct cooling of an electronic chip of 25mm x 25mm in size is analyzed as a function of channel geometry for single-phase flow of water through small hydraulic diameters. Fully developed laminar flow is considered ... -
Effect of gravitational orientation on flow boiling of water in 1054 x 197 micron parallel minichannels
(American Society of Mechanical Engineers (ASME), 2004-06)Microchannels and minichannels are being considered for high heat flux applications under microgravity environment in space missions. Due to the small hydraulic diameter, the effect of gravitational forces on flow boiling ... -
Evaluation of single phase flow in microchannels for high flux chip cooling - Thermohydraulic performance enhancement and fabrication technology
(American Society of Mechanical Engineers (ASME), 2004-06)The increased circuit density on today’s computer chips is reaching the heat dissipation limits for air-cooled technology. Direct liquid cooling of chips is being considered as a viable alternative. This paper reviews ...