Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Finite Volume Method

Numerical Investigation of Energy Storage in Packed Bed of Cylindrical Capsules of PCM

Ahmed K. Alshara; Mohammed Kh. Kadhim

Engineering and Technology Journal, 2014, Volume 32, Issue 2, Pages 494-510

A theoretical study of storage thermal energy using capsulated cylinders filled with phase change material PCM is performed. These cylinders are arranged in-line in the direction of heat transfer fluid. The energy equations of fluid (water) and PCM capsules are solved numerically using finite volume method with heat capacity method for phase change of PCM. The effect of Reynolds number and the ratio of pitch to diameter of the cylinders on the temperature distribution and melt fraction are presented. The results show that the increment of both Reynolds number and the ratio of the pitch to diameter gives decrement in the final time of melting of PCM in the cylinders.

Numerical and Experimental Analyses for Effect of Welding Currents on Cooling Rates in (M MAW) Process

Abbas Sh. Alwan; Jalal M. Jalil; Muna K. Abbass

Engineering and Technology Journal, 2010, Volume 28, Issue 12, Pages 2276-2293

In this study, Manual Metal Arc Welding (MMAW) is carried out for low
carbon steel (AISI 1015) with using electrode (E7018). Direct current straight
polarity (DCSP) with the joint geometry of single -V- butt joint and weld one pass
are used for plate of thickness 8mm. experimentally, obtained temperature
distribution in fusion zone which is measured by insert the thermocouple in weld
metal. Cooling rates are determined for the fusion zone at different welding
currents (100, 120 and 140) Amp with constant welding speed at 3.2mm/s.
Numerical analysis by using the Control Volume Method (CVM), applied to threedimensional
heat transfer model to determine the cooling rate in fusion zone.
Cooling rates models are helping in prediction the microstructure (phases, grain
size and volume fraction) and microhardness distribution in weld metal and heat
affected zone. The comparison of cooling curves between numerical and
experimental work have a good agreement, so that deviation was in range ( 6℅ -
21℅) which is confirming the capability and reliability of the proposed numerical
heat transfer model in manual metal arc welding. The best result for cooling rates
when applying mathematical model is at welding current 140Amp.