Experimental Investigation of Oscillation Controlled Thermal Transport in Water-Based Nanofluids

2016 ◽  
Author(s):  
Oguz Guven ◽  
Murat K. Aktas ◽  
Yildiz Bayazitoglu
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Pipe Flow ◽  
Low Frequency ◽  
Measured Temperature ◽  
Maximum Displacement ◽  
Vibration Displacement ◽  
Experimental Apparatus ◽  
Frequency Regime ◽  
Bottom Side

The oscillatory flows are often in order to augment heat transfer rates in various processes. It is also well known fact that nanofluids provide significant enhancement in heat transfer at certain conditions. In this research, heat transfer in an oscillatory pipe flow of both water and water-alumina nanofluid were studied experimentally under low frequency regime flow conditions. The aim of the conducted research is parametric experimental investigation of the convective heat transfer in the oscillatory pipe flow. Firstly, the nanofluids were prepared and thermophysical properties weare measured. The experimental apparatus consist of a capillary pipe bundle connecting two reservoirs which are placed at the top and bottom side of the capillary pipe bundle. Upper reservoir contains the hot fluid while lower reservoir and capillary pipe bundle filled with cold fluid. The oscillatory flow in the pipe bundle is driven by the periodic vibrations of a surface mounted on the bottom end of the cold reservoir. The effects of the maximum displacement amplitude of the vibrations and volumetric concentration of nanoparticles on heat transfer were evaluated based on the measured temperature and acceleration data. It is found that heat transfer rate increases with increasing vibration displacement in the fluid.

Experimental Investigation of Oscillation Controlled Heat Transport Tubes

2015 ◽  
Author(s):  
Omer F. Guler ◽  
Murat K. Aktas
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Pipe Flow ◽  
Thermal Transport ◽  
Low Frequency ◽  
Maximum Displacement ◽  
Vibration Displacement ◽  
Oscillatory Flows ◽  
Pure Diffusion ◽  
Experimental Apparatus

The oscillatory flows are widely used to enhance heat transfer or as an alternative cooling technique. The oscillatory flows in liquids have the potential of augmenting heat transfer as demonstrated in literature. The subject needs to be investigated in order to fully understand the thermal transport mechanism and affecting parameters. In this investigation, heat transfer in an oscillatory pipe flow of water was studied, experimentally for low frequency regime flow conditions. Major research tasks are; setting up of the experimental apparatus, parametric experimental investigation of the convective heat transfer in oscillatory pipe flow and data reduction and analysis. An experimental apparatus was designed and constructed for the experimental investigation. The equipment consist a capillary pipe bundle connecting a cold fluid and a hot fluid reservoir. The effects of the maximum displacement amplitude of the vibrations and vibration frequency on the heat transfer were analyzed with a parametric study. Significant effect of oscillatory flow on the thermal transport compare to pure diffusion was measured. The heat transfer is greatly enhanced as vibration displacement increase. The results of the present investigation will be useful in choosing optimum operation parameters for cooling applications utilizing oscillatory flows.

Heat Transfer Enhancement by Sinusoidal Motion of a Water-Based Nanofluid

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Omer F. Guler ◽  
Oguz Guven ◽  
Murat K. Aktas
Keyword(s):  
Heat Transfer ◽  
Capillary Tube ◽  
Tube Bundle ◽  
Measured Temperature ◽  
Maximum Displacement ◽  
Maximum Heat ◽  
Transfer Rates ◽  
High Heat Transfer ◽  
Maximum Heat Transfer ◽  
Experimental Apparatus

The oscillatory flows are often utilized in order to augment heat transfer rates in various industrial processes. It is also a well-known fact that nanofluids provide significant enhancement in heat transfer at certain conditions. In this research, heat transfer in an oscillatory pipe flow of both water and water–alumina nanofluid was studied experimentally under low frequency regime laminar flow conditions. The experimental apparatus consists of a capillary tube bundle connecting two reservoirs, which are placed at the top and the bottom ends of the capillary tube bundle. The upper reservoir is filled with the hot fluid while the lower reservoir and the capillary tube bundle are filled with the cold fluid. The oscillatory flow in the tube bundle is driven by the periodic vibrations of a surface mounted on the bottom end of the cold reservoir. The effects of the frequency and the maximum displacement amplitude of the vibrations on thermal convection were quantified based on the measured temperature and acceleration data. It is found that the instantaneous heat transfer rate between de-ionized (DI) water (or the nanofluid)-filled reservoirs is proportional to the exciter displacement. Significantly reduced maximum heat transfer rates and effective thermal diffusivities are obtained for larger capillary tubes. The nanofluid utilized oscillation control heat transport tubes achieve high heat transfer rates. However, heat transfer effectiveness of such systems is relatively lower compared to DI water filled tubes.

Heat Transfer From an Oscillating Horizontal Wire to Water and Ethylene Glycol

1966 ◽  
Vol 88 (4) ◽  
pp. 359-363 ◽  
Author(s):  
W. R. Penney ◽  
T. B. Jefferson
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Ethylene Glycol ◽  
Mixed Convection ◽  
Large Amplitude ◽  
Previous Investigation ◽  
Low Frequency ◽  
Fluid Properties ◽  
Correlate Data ◽  
Horizontal Wire

An experimental investigation has been conducted to investigate the effect of low-frequency, large-amplitude, horizontal oscillations on convection from a heated horizontal wire (0.008 in. dia) to water and ethylene glycol. Frequencies to 4.5 cps and amplitudes to 2.5 in. were employed. Comparison with a previous investigation has shown that, in the range of this investigation, heat transfer for vertical oscillations is greater than for horizontal oscillations. Comparison of data for water and ethylene glycol showed that previous methods of presenting mixed convection (free plus forced convection) data would not suffice for widely varying fluid properties. A correlating method was developed which successfully correlated the data of this investigation but failed to correlate data of previous investigations. Deficiencies of this method are discussed, and recommendations are given for future correlating methods.

Development of Film Cooled Thruster for Rocket Application

2019 ◽  
Author(s):  
Avanish Kumar ◽  
V. Venkateswarlu ◽  
P. Satyaprasad ◽  
M. Raghavendra Rao
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Film Cooling ◽  
Infrared Camera ◽  
Outer Wall ◽  
Pulse Mode ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Core Flow ◽  
Bottom Side

Abstract An experimental investigation has been carried out for small liquid bi-propellant thrusters of 490 & 1500 N levels. These thrusters have to operate for more than 100 sec in continuous and pulse mode. In this case, film cooling is the primary mode of thruster cooling. The thruster uses hydrazine based propellant as fuel and N2O4 as oxidiser. Film cooling is carried out by injecting a fraction of fuel from an injector periphery. Unlike impinging type injection elements are used for core flow. The thruster’s shell used for testing was made of stainless steel and di-silicide coated C103 material. A 1D heat transfer model was developed for predicting the thruster outer wall temperature. The experimental investigation was carried for different film cooling percentage and injector configuration was modified for each case. Thermocouples were mounted on top & bottom side of shell for temperature measurement. Infrared camera also used for recording temperature in the test. Based on experimental investigation, effective film cooling percentage for optimum thruster performance has been estimated for two thrust levels and these studies also helped in validating the heat transfer model.

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