Experimental Investigation of the Thermal Performance of a Manifold Hierarchical Microchannel Cold Plate

2011 ◽  
Author(s):  
Ercan M. Dede
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Flat Plate ◽  
Single Phase ◽  
Optimization Technique ◽  
Jet Impingement ◽  
Measured Temperature ◽  
Cold Plate ◽  
Temperature And Pressure ◽  
Plate System

This article is focused on experimental investigation of the single-phase thermal-fluid performance of a manifold microchannel cold plate with integral hierarchical branching channels. The use of a multiphysics topology optimization technique for the development of the studied microchannel structure is briefly reviewed. An experimental test setup is then described followed by measured temperature and pressure results. Specifically, unit thermal resistance and pressure drop values for the hierarchical microchannel jet impingement cold plate are compared with corresponding results for the jet impingement of a flat plate. These experiments confirm that the hierarchical microchannel system provides increased heat transfer with a negligible change in pressure drop when compared with the standard flat plate system.

scholarly journals Experimental Investigation of the Vertical Upward Single- and Two-Phase Flow Pressure Drops Through Gate and Ball Valves

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Ammar Zeghloul ◽  
Hiba Bouyahiaoui ◽  
Abdelwahid Azzi ◽  
Abbas H. Hasan ◽  
Abdelsalam Al-sarkhi
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Single Phase ◽  
Gate Valve ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Flow Conditions ◽  
Two Phase ◽  
Pressure Drops ◽  
Flow Pressure

Abstract This paper presents an experimental investigation of the pressure drop (DP) through valves in vertical upward flows. Experiments were carried out using a 1¼″ (DN 32) ball and gate valve. Five opening areas have been investigated from fully open to the nearly fully closed valve, using air with a superficial velocity of 0–3.5 m/s and water 0.05–0.91 m/s. These ranges cover single-phase and the bubbly, slug and churn two-phase flow regimes. It was found that for the single-phase flow experiments, the valve coefficient increases with the valve opening and is the same, in both valves, for the openings smaller than 40%. The single-phase pressure drop increases with the liquid flowrate and decreases with the opening area. The two-phase flow pressure drop was found considerably increased by reducing the opening area for both valves. It reaches its maximum values at 20% opening for the ball valve and 19% opening for the gate valve. It was also inferred that at fully opening condition, the two-phase flow multiplier, for both valves, has been found close to unity for most of the tested flow conditions. For 40 and 20% valve openings the two-phase multiplier decreases in the power-law with liquid holdup for the studied flow conditions. Models proposed originally for evaluating the pressure drop through an orifice in single-phase and two-phase flows were also applied and assessed in the present experimental data.

Experimental Investigation of a Flat-Plate Closed-Loop Pulsating Heat Pipe

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Wessel W. Wits ◽  
Gerben Groeneveld ◽  
Henk Jan van Gerner
Keyword(s):  
Experimental Investigation ◽  
Flat Plate ◽  
Heat Pipe ◽  
Closed Loop ◽  
Electronics Cooling ◽  
Power Input ◽  
Working Fluid ◽  
Pulsating Heat Pipe ◽  
Thermo Electric ◽  
Temperature And Pressure

The thermal performance and operating modi of a flat-plate closed-loop pulsating heat pipe (PHP) are experimentally observed. The PHP is manufactured through computer numerical controlled milling and vacuum brazing of stainless steel 316 L. Next to a plain closed-loop PHP, also one that promotes fluid circulation through passive Tesla-type valves was developed. Each channel has a 2 × 2 mm2 square cross section, and in total, 12 parallel channels fit within the 50 × 200 mm2 effective area. During the experimental investigation, the power input was increased from 20 W to 100 W, while cooling was performed using a thermo-electric cooler (TEC) and thermostat bath. Three working fluids were assessed: water, methanol, and ammonia. The PHP was charged with a 40% filling ratio. Thermal resistances were obtained for different inclination angles. It was observed that the PHP operates well in vertical evaporator-down orientation but not horizontally. Moreover, experiments show that the minimum operating orientation is between 15 and 30 deg. Two operating modi are observed, namely, the thermosyphon modus, without excessive fluctuations, and the pulsating modus, in which both the temperature and pressure responses oscillate frequently and violently. Overall thermal resistances were determined as low as 0.15 K/W (ammonia) up to 0.28 and 0.48 K/W (water and methanol, respectively) at a power input of 100 W in the vertical evaporator-down orientation. Infrared thermography was used to visualize the working fluid behavior within the PHPs. Infrared observations correlated well with temperature and pressure measurements. The experimental results demonstrated that the developed flat-plate PHP design, suitable for high-volume production, is a promising candidate for electronics cooling applications.

Numerical Simulation of a Novel Jet-Impingement Micro Heat Sink With Cross Flow Under Non Uniform Heating Condition

2011 ◽  
Author(s):  
Yanfeng Fan ◽  
Ibrahim Hassan
Keyword(s):  
Numerical Simulation ◽  
Heat Flux ◽  
Pressure Drop ◽  
Flat Plate ◽  
Heat Sink ◽  
Cross Flow ◽  
Jet Impingement ◽  
Jet Flow ◽  
Maximum Temperature ◽  
Cooling Performance

A novel micro heat sink applying the jet-impingement and cross flow is proposed to dissipate the heat from the electrical devices. Six hotspots of 2 mm × 2 mm are positioned on a flat plate of 25.4 mm × 25.4 mm. The area of flat plate except the hotspots is provided a constant heat flux of 20 W/cm2 as background heating source among cases. Four heat fluxes from 40 to 100 W/cm2 on the hotspots are tested to simulate the different operation conditions. The cross flow is used to remove the background heat flux and jet flow is supplied into the swirl microchannel, located at the right top of hotspot, to dissipate the large heat flux from hotspots. The channel depth is 0.5 mm and the width of swirl microchannel is 0.38 mm. The cross flow and jet flow velocity vary from 0.1 m/s to 0.5 m/s and from 0.5 m/s to 2 m/s, respectively. The effects of cross flow and jet flow on the cooling performance are investigated by numerical simulation. The local heat transfer coefficient and Nusselt number are calculated to evaluate the cooling performance of proposed micro heat sink for the targets of low maximum temperature, temperature gradient and pressure drop. The results show that the maximum temperature of the proposed design occurred at the outlet is approximately 65 °C among tested cases. The corresponding pressure drop is 5.5 kPa. The overall thermal resistance reaches as small as 0.23 K/W.

Experimental investigation of pressure drop in failed Electrical Submersible Pump (ESP) under liquid single-phase and gas-liquid two-phase flow

2021 ◽  
Vol 198 ◽  
pp. 108127
Author(s):  
William Monte Verde ◽  
Jorge Biazussi ◽  
Cristhian Estrada Porcel ◽  
Valdir Estevam ◽  
Alexandre Tavares ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Single Phase ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Submersible Pump ◽  
Two Phase ◽  
Electrical Submersible Pump

scholarly journals Modeling, simulation and experimental investigation of closed loop MPPT based single phase stand alone photo voltaic system using particle swarm optimization technique

2018 ◽  
Vol 7 (2.21) ◽  
pp. 94
Author(s):  
P V. Thakre ◽  
V M. Deshmukh
Keyword(s):  
Experimental Investigation ◽  
Particle Swarm Optimization ◽  
Single Phase ◽  
Closed Loop ◽  
Optimization Technique ◽  
Particle Swarm ◽  
Swarm Optimization ◽  
Loop Control ◽  
Novel Approach ◽  
Particle Swarm Optimization Technique

Standalone photovoltaic (PV) systems are implemented to perform independently from the utility grid. Such system are beneficial for certain AC as well as DC loads; that too especially where conventional energy cannot reach. To make such system more efficient and independent, a closed loop control could be employed. This research paper presents a novel approach to model and simulate a closed loop maximum peak power tracking (MPPT) based single phase stand alone system using particle swarm optimization (PSO) technique. Based on the simulation results, an experimental investigation has been successfully carried out. 

scholarly journals Drag Reduction Properties of Nanofluids in Microchannels

2015 ◽  
Vol 12 (2) ◽  
pp. 60 ◽  
Author(s):  
H.A. Abdulbari ◽  
F.L.W. Ming
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Drag Reduction ◽  
Single Phase ◽  
Critical Concentration ◽  
Primary Objective ◽  
Experimental Results ◽  
Water Suspensions ◽  
Micro Channels

An experimental investigation of the drag reduction (DR) individualities in different sized micro channels was carried out with nanopowder additives (NAs) (bismuth(III) oxide, iron(II/III) oxide, silica, and titanium(IV) oxide) water suspensions/fluids. The primary objective was to evaluate the effects of various concentrations of NAs with different microchannel sizes (50, 100, and 200 µm) on the pressure drop of a system in a single phase. A critical concentration was observed with all the NAs, above which increasing the concentration was not effective. Based on the experimental results, the optimum DR percentages were calculated. The optimum percentages were found to be as follows: bismuth III oxides: ~65% DR, 200 ppm and a microchannel size of 100 µm; iron II/III oxides: ~57% DR, 300 ppm, and a microchannel size of 50 µm; titanium IV oxides: ~57% DR, 200 ppm, and a microchannel size of 50 µm, and silica: 55% DR, 200 ppm, and a microchannel size of 50 µm.  

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