Papers by Keyword: Heat Transfer Analysis

Abstract: The study presents the design of a highly efficient cooking stove for rural applications, along with performance evaluation. Drawing on diverse literature, existing works were analysed to derive design enhancements. Utilizing SolidWorks and Creo, a model was constructed, followed by material selection and cost analysis using accessible market components. ANSYS Fluent enabled flow analysis for both optimal and real configurations, complemented by experimental tests for validation. Results underscore the stove's efficiency, evident in reduced wood consumption for cooking and decreased soot generation. Significantly, the system's heat transfer rate reached 11.67°C/min, outperforming open stoves at 3.42°C/min, while maintaining affordability at RM 415.34. Nomenclature = Temperature transfer efficiency for heat recovery = Temperature outside air before entering system = Temperature inside air after system heat transfer has occurred = Temperature inside air before system is switched on = Temperature Transfer Efficiency for Heat Loss

Abstract: Microchannel heat sink plays a vital role in removing a considerable amount of heat flux from a small surface area from different electronic devices. In recent times, the rapid development of electronic devices requires the improvement of these heat sinks to a greater extent. In this aspect, the selection of appropriate substrate materials of the heat sinks is of vital importance. In this paper, three boron-based ultra-high temperature ceramic materials (ZrB₂, TiB_2, and HfB₂) are compared as a substrate material for the microchannel heat sink using a numerical approach. The fluid flow and heat transfer are analyzed using the finite volume method. The results showed that the maximum temperature of the heat source didn’t exceed 355K at 3.6MWm^-2 for any material. The results also indicated HfB₂ and TiB₂ to be more useful as a substrate material than ZrB₂. By applying 3.6 MWm^-2 heat flux at the source, the maximum obtained surface heat transfer coefficient was 175.2 KWm^-2K^-1 in a heat sink having substrate material HfB₂.

Abstract: Molten carbonate fuel cells (MCFCs) are high-temperature fuel cells that use liquid electrolytes composed of molten carbonates such as Li₂CO₃, Na₂CO₃, and K₂CO₃. Electrochemical reactions of MCFCs are exothermic reaction. Consequently, temperature distribution of fuel cells is one of important factors in long-term operation. In this work, the effects of the size of the fuel cell on the temperature distribution were investigated using CFD analysis. It was found that as the length of the gas flow direction and the number of layers of fuel cell increases, the maximum temperature of the cell was increased.

Abstract: Recently, consumers are often dissatisfied with the battery life from even the most advanced lithium-ion rechargeable batteries in mobile phone. A mobile battery was chosen in this study because it is the flat plate of small thin wall which is expected to have some flexing. It is required to be evaluated and designed considering the coupled phenomena. Especially, this paper describes a meshless of element-free method based on fuzzy knowledge processing for battery of smart phone. Practical performance of the present method is demonstrated through heat conduction analysis.

Abstract: The finite volume simulation of equal channel angular pressing (ECAP) was realized using 3D commercial code MSC.SuperForge. The knowledge of stress and temperature during ECAP process is very important for forming a hard-to-deform as Ti under optimal thermo-mechanical conditions to achieve desired mechanical properties. In this work, the strain, stress and temperature fields of both the die and workpiece are studied. The resulted stress and temperature distributions showed maximal values in the region of corner and channel angles of the die. Also, the temperature increased during the processing, as a consequence of the deformation. The heating of the deformation system was calculated and analyzed for three different ram speeds (v = 1, 10 and 20 mm/s) at 400 °C. Keywords: ECAP, SPD, FEM, FVM, heat transfer analysis, titanium

Abstract: The effect of melt temperature on the interfacial thermal resistance and solidification behaviour of A356/10% SiC_p during squeeze casting is studied. The melt pouring temperatures are considered in the investigation within the range of 750 - 900°C respectively. The squeeze pressure is kept constant at 100 MPa. It was observed that the solidification time increased with the melt temperature from 40 seconds at 750°C to 51 seconds at 900°C. The results also showed that the cooling rate decreased with melt temperatures. The solidification time calculated from the theoretical expression was found to be in good agreement with that obtained from the experimental cooling curves. The interfacial thermal resistance value increases from 0.000043 to 0.000203 m² K/W when the melt temperature is increased from 750 to 900°C.

Abstract: The time-varying temperature field and stress distribution of a concrete roof slab is actively investigated in this study with the aiding of the commercial package ANSYS. Fine finite element model of the concrete slab is constructed and different boundary conditions are applied to obtain the temperature distribution within the slab. The solar radiation model is utilized to estimate the solar radiation received by the slab and the shelter effects are also taken into consideration. The numerical models can successfully predict the structural temperature gradient and thermal stress distribution at different time. The made observations indicate that the simulated temperature variation of the concrete slab based on the solar radiation model agrees well with measurement results. It is seen that the numerical models can successfully predict the structural time-varying thermal effects.

Abstract: The dynamic temperature field of a concrete slab is actively studied in this study with the aiding of the commercial package ANSYS. Fine finite element model of the concrete slab is constructed and different boundary conditions are applied to obtain the temperature distribution within the slab with the aid of the commercial software package ANSYS. The solar radiation model is utilized to estimate the solar radiation received by the slab and the shelter effects are also taken into consideration. The numerical models can successfully predict the structural temperature at different time. The made observations demonstrate that the simulated temperature variation of the concrete slab based on the solar radiation model agrees well with measurement results. It is seen that the numerical models can successfully predict the structural temperature field at different time. The methodology employed in the paper can be applied to other concrete structures as well.

Abstract: The chiller performance decrease with the system operating is inevitable, however, determining how to predict when it will happen, and how to identity the degree of performance decline, it is very important to solve these actual problems for chiller high efficiency operating and daily management. This paper developed a fault diagnosis model based on thermodynamic analysis of chiller’s refrigeration cycle and heat transfer analysis of its heat exchangers, taking three projects which involve different source sinks, namely, air source, ground source and reclaimed water source as cases study, described the fault diagnosis method and implementation steps through these engineering cases, the results show that the fault diagnosis model provides a newly simple and effective approach for chiller operation monitoring.

Abstract: Bridge tower, time-varying temperature field, heat transfer analysis, finite element model. Abstract. Long span suspension bridges are subjected to daily, seasonal and yearly environmental thermal effects induced by solar radiation and ambient air temperature. This paper aims to investigate the temperature distribution of a tower of a long span suspension bridge. Two-dimensional heat transfer models are utilized to determine the time-dependent temperature distribution of the bridge tower of the bridge. The solar radiation model is utilized to examine the time-varying temperature distribution. Finite element models are constructed for the bridge tower to compute the temperature distribution. The numerical models can successfully predict the structural temperature field at different time. The methodology employed in the paper can be applied to other long-span bridges as well.