Time-varying heat transfer coefficients between tube-shaped casting and metal mold

Experimental determination of heat transfer coefficients during squeeze casting of aluminium

“…The maximum heat transfer coefficients of 2927.92 W/m 2 K and 2975.14 W/m 2 K are obtained at the cylindrical and bottom flat surfaces respectively for no pressure application, which is close to 2900 W/m 2 K as obtained for pure aluminium by Kim and Lee (1997). The values of heat transfer coefficients decrease rapidly for both the cylindrical and bottom flat surfaces to a level of 866.70 W/m 2 K and 969.50 W/m 2 K respectively in 90 seconds.…”

An Analytical Solution for Transient Heat Conduction in a Composite Slab with Time-Dependent Heat Transfer Coefficient

“…The surface HTCs of the fuel elements in a boiling water reactor and a pebble bed reactor also vary over time [2]. The same holds for the HTCs between a casting and its metal moulds [3], on diesel fuel droplets subjected to transient heating [4], and on solids enveloped by pulsating flows of liquid or gas in internal combustion engines [5]. In addition, during the thermal processing of foods, the pattern of air circulation may be altered around them, resulting in changes of the surface HTC [6].…”

Assessment of Computer Simulation Software and Process Data for High Pressure Die Casting of Magnesium

“…First, the HTC has a minimum at about 30-40s since the onset of pouring, increasing afterwards by an amount of approximately of 500 W/m 2 . In order to rule out systematic errors due to temperature measurements, the HTC was computed using the surface casting temperature, Kim and Lee (1997), for aluminum alloy A356 cast into steel mold with a graphite coating. Another possible explanation of this HTC behavior is related to the use of a sensor material different than the mold material.…”