scholarly journals Heat Transfer Studies on Solidification of Casting Process

2021 ◽  
Author(s):  
L. Anna Gowsalya ◽  
Mahboob E. Afshan
Keyword(s):  
Heat Transfer ◽  
Casting Process ◽  
Industrial Applications ◽  
Sand Mold ◽  
Heat Transfer Mechanism ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Complex Shapes ◽  
Transfer Behavior ◽  
Shrinkage Behavior

This chapter deals with the heat transfer characteristics between the cast and the mold. Generally the heat transfer behavior between the cast and the sand mold is used and all the three modes of heat transfer are studied. The heat transfer characteristics from the cast is at a faster rate for a die mold than for the sand mold. Since the sand mold is used for most of the industrial applications for the complex shapes of metal the heat transfer and the shrinkage behavior in solidification has to be understood perfectly. In this chapter, since the heat transfer mechanism and the shrinkage behavior of the metal in the sand mold is interrelated, hence were predominantly discussed.

Local and Instantaneous Heat Transfer Characteristics of Arrays of Pulsating Jets

1999 ◽  
Vol 121 (2) ◽  
pp. 341-348 ◽  
Author(s):  
H. S. Sheriff ◽  
D. A. Zumbrunnen
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Jet Flow ◽  
Impinging Jets ◽  
Industrial Applications ◽  
Heat Transfer Characteristics ◽  
Ensemble Averaging ◽  
Transfer Characteristics ◽  
Pulsating Jets

Recent investigations have revealed that pulsations in an incident jet flow can be an effective technique for modifying convective heat transfer characteristics. While these studies focused on single impinging jets, industrial applications of impinging jets usually involve arrays of jets. To explore the effects of flow pulsations on the heat transfer performance of jet arrays, an experimental investigation has been performed of instantaneous and time-averaged convective heat transfer to a square, in-line array of circular air jets within an unit cell of the array. Hot-film anemometry was used to document the jet flow field. Instantaneous and time-averaged convective heat transfer rates were measured using a heat flux microsensor. An ensemble averaging technique was used to separate the pulsating component of flow velocity and heat transfer from the turbulent components and thereby assess the effect of flow pulsation on turbulence intensity and heat transfer. For the ranges of parameters considered, results indicate convective heat transfer distributions become more uniform in response to pulsations but heat transfer is not enhanced. Improved uniformity can be a useful aspect in many jet applications.

Effect of Blockage-Ratio on Developing Heat Transfer for a Rectangular Duct With Transverse Ribs

2013 ◽  
Author(s):  
Zahra Ghorbani-Tari ◽  
Lei Wang ◽  
Bengt Sunden
Keyword(s):  
Heat Transfer ◽  
Rectangular Channel ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Uniform Heat Flux ◽  
Blockage Ratio ◽  
Heat Transfer Characteristics ◽  
Liquid Crystal Thermography ◽  
Transfer Characteristics ◽  
Transfer Behavior

The developing heat transfer characteristics in a rectangular channel (AR = 4) equipped with continuous transverse ribs are experimentally investigated. The ribs were regularly spaced over a section of the channel which was heated by a uniform heat flux. The blockage ratio e/Dh varied from 0.039 to 0.078. Two values of the rib pitch to rib height ratio (10 and 20) were considered, with the Reynolds number from 57,000 to 127, 000. The studied geometry is relevant to turbine structures between high pressure and low pressure turbines in aircraft engines. The maps of local heat transfer coefficient in the inter-rib regions were obtained by using the steady state liquid crystal thermography. The main purpose is to investigate the effect of blockage ratio (e/Dh) on the developing heat transfer behavior. In particular, the heat transfer characteristics between the first repeated ribs, i.e., in the inter-rib regions were studied, where the flow field is fully developed while the thermal field is not yet periodically fully developed.

INVESTIGATION OF HEAT TRANSFER CHARACTERISTICS OF MGMNNI/DIW-BASED NANOFLUIDS FOR QUENCHING IN INDUSTRIAL APPLICATIONS

2015 ◽  
Vol 22 (1) ◽  
pp. 1-28 ◽  
Author(s):  
Subbiah Rammohan Chitra ◽  
Sechasalom Sendhilnathan ◽  
Sivan Suresh
Keyword(s):  
Heat Transfer ◽  
Industrial Applications ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics

Numerical investigation of fluid flow and heat transfer characteristics in novel circular wavy microchannel

2018 ◽  
Vol 233 (5) ◽  
pp. 954-966 ◽  
Author(s):  
Valaparla Ranjith Kumar ◽  
Karthik Balasubramanian ◽  
K Kiran Kumar ◽  
Nikhil Tiwari ◽  
Kanishk Bhatia
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Fluid Flow ◽  
Constant Heat Flux ◽  
Heat Transfer Characteristics ◽  
Number Range ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Centrifugal Instability ◽  
Transfer Behavior

In this study, the fluid flow and heat transfer behavior in a novel circular wavy microchannel design is numerically examined and compared with a sinusoidal wavy microchannel. The numerical studies were carried out in the Reynolds number range of 100–300 under a constant heat flux wall boundary condition. The sinusoidal profile has a continuously varying curvature, which peaks at the crests and troughs, and diminishes to naught at each section at the middle of adjacent crests and troughs. On the other hand, the circular profile has a curvature constant in magnitude (and alternating in direction). Heat transfer in wavy microchannels is enhanced by vortex flow induced by centrifugal instability, which in turn depends on the curvature of fluid channel profile. The sinusoidal wavy microchannel has a curvature continuously varying in a large range results in large fluctuations of Nusselt number, while the Nusselt number in the circular channel has smaller fluctuations. Hence, heat transfer performance of the circular wavy microchannel is higher than that of the sinusoidal wavy microchannel. Velocity vectors, velocity contours, and temperature contours are presented to aid the explanation of hydrodynamic and heat transfer characteristics of fluid flow in the novel circular wavy microchannels. The Nusselt number and pressure drop along the channel are also compared with the sinusoidal wavy microchannel using a performance factor.

Heat Transfer Characteristics in Mist Cooling With Machining Oil

2005 ◽  
Author(s):  
Hiroyasu Ohtake ◽  
Tomoyasu Tanaki ◽  
Yasuo Koizumi
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Heated Surface ◽  
Water Mist ◽  
Transfer Mechanism ◽  
Heat Transfer Mechanism ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Oil Mist ◽  
Mist Cooling

Heat transfer characteristics in mist cooling with commercial machining oil were investigated experimentally. Steady state experiments of heat transfer were conducted using a pure copper cylinder and mist flow of commercial machining oil and air. Liquid flow rate was 0.3, 0.9, 1.8, 4 and 8 l/hr, respectively; each air flow rate was 0, 40, 75 and 120 lN/min. Furthermore, liquid mass flux on the heating surface for each experimental condition was measured by using a measuring cylinder with same diameter as the heater. Average velocity of droplets and average diameter of those were measured by using a laser doppler anemometer and immersion method, respectively. The heat transfer mechanism in oil mist was only cooling of liquid film formed on a heated surface, whereas the heat transfer mechanism in water mist cooling was classified into three regions. The heat transfer coefficient in the oil mist was well expressed by the heat removal capacity on sensible heat of supplying oil-droplets to the heated surface. Four dimensionless correlations were derived from a dimension analysis, Buckingham Pi theorem, and experimental data for both water mist and the oil mist.

Heat transfer characteristics of lost foam casting process of magnesium alloy

2006 ◽  
Vol 16 (2) ◽  
pp. 445-451 ◽  
Author(s):  
Zi-li LIU ◽  
Qing-lin PAN ◽  
Zhao-feng CHEN ◽  
Xi-qin LIU ◽  
Jie TAO
Keyword(s):  
Heat Transfer ◽  
Magnesium Alloy ◽  
Casting Process ◽  
Lost Foam Casting ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Lost Foam
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