Papers by Keyword: Thermal Modeling

Abstract: This study investigates the thermal field of S355J2+N steel plates for shipbuilding applications welded with automatic welding equipment. Real-time thermal profiles were captured and validated using infrared thermography against SolidWorks simulations. Experimental data revealed maximum weld pool temperatures of 528 °C and sharp thermal gradients in the heat-affected zone (HAZ). The numerical model, which predicts a peak temperature of 670°C, closely matched the experimental results. An empirical relationship between welding parameters and maximum welding temperature was derived, allowing optimization of heat input and welding speed to minimize thermal distortions and residual stresses. This integrated approach improves process control and weld quality in shipbuilding.

Abstract: In this manuscript, a new concept of power generation from thermoelectric generators TEGs using the sun irradiation and two oil tanks, one hot and one cold, is proposed. It consists of two oil tanks separated by a plate covering several TEGs in series. The oil tank at the bottom of the system constitutes a cold convection condition for the TEGs plate; on the other hand, the upper oil tank accounts for a hot convection condition since its upper surface is transparent and therefore subjected to the sun irradiation that will heat up the oil. To test the feasibility of this concept, an appropriate thermal modeling is developed and associated parametric analysis was carried out. It shows that powers up to 242 W can be generated with a system having a hot oil tank height of 0.2 m along with a width and length of 2 m each.

Abstract: A hybrid greenhouse effect dryer was examined for small-medium cracker industries. The system consists of a main drying chamber, biomass stove, heat exchanger, and shelf. This work aims to construct heat and mass transfer model which can describe well the drying process, as well as can be used to predict the greenhouse air temperature, product temperature, and moisture evaporation during drying. Drying is conducted in the room dryer for 9 samples of crackers where each sample is ± 150 grams and is divided into 3 samples placed on the bottom shelf, 3 samples on middle shelf, and 3 samples on the top shelf. Drying is carried out from the initial moisture content of crackers ± 63‒64% to 12‒14% for the standard fries. Mathematics model was simulated in MATLAB software and was validated by comparing the analytical and experimental result. The heat transfer model could describe well the heat transfer process during drying. It was shown that the analytical and experimental results are in good agreement, with mean error range values 5.38‒20.4%.

Abstract: The paper proposes the approach for the thermal through process modelling of the strip hot rolling chain of magnesium alloys. This strip hot rolling chain comprises the coil reheating after the Twin-Roll Casting (TRC) process, storage or transport operations and reversing hot rolling. The modelling of reversing rolling is implemented in connection with the simultaneous un-/coiling process of a coil. The numerical calculation is based on an object-oriented FEM tool kit written in MATLAB™ and is carried out in three spatial dimensions and time.

Abstract: This paper introduces a concept for the simulation of temperature distribution in reversing hot rolling of magnesium strip. The technological chain consists of reheating the casted rough strip, carrying the coil form furnace to coiler, setting down on mandrel, and hot reversing rolling. The paper represents the current state of work. The numerical calculation is based on an object-oriented FEM toolkit written in MATLAB™ and is carried out in three spatial dimensions and time.

Abstract: In this paper thermal simulation of a satellite borne electric box is introduced. Structure was simplified and a finite element model was built. The analysis results showed that the temperature scopes of the box and the component cases are from 45°C to 67.3°C and all of junction temperatures of the components are lower than the derated maximum junction temperatures themselves and leave enough design margins, which match the requirements of thermal analysis.

Abstract: This study developed a thermal model of a photovoltaic thermal collector (PVT) to predict the performance and outlet temperature of the system. The PVT consisted of a polycrystalline photovoltaic module, a polymer collector–type sheet in a tube, and an insulator. The motivation of the present work is that the polymer materials are flexible, low cost and lightweight which are for the PVT applications. The outlet temperature of the PVT increased with the decreasing rate of mass flow into the riser because the water had sufficient time for thermal heating. One unit of polymer collector can achieve an outlet temperature of 69 °C at 500 W/m² at a mass flow rate of 0.0063 kg/s.

Abstract: Thermal modeling is a method used to formulate a temperature profile for a generator. The most common types of thermal model used by researchers are transient and steady-state model. There is insufficient of information regarding prolong usage of a generator in a confined space. The purpose of this paper is to formulate an empirical temperature model for the winding coils for the duration of 24 hours and to investigate whether a peak temperature exists. From the results, it can be concluded that there is a peak temperature detected for the winding coils in a non-controlled room temperature that occurs after 9 hours of experiment. The effect of room temperature on the winding coils temperature for no load condition is only 6.6%.

Abstract: In order to develop a thermal model for a generator or a motor, several experiments need to be conducted. One of the challenges in conducting the experiment is that it consumes a lot of time to reach its steady state condition. This is because a generator or a motor has a lot of moving parts and a large amount of surface area causes a very slow rise in temperature. This paper proposes a new method to reduce the experimental time by estimating the settling time using a modeling technique used in the control system engineering. From the data presented, the experimental time can be reduced approximately 55 percent. Furthermore, it is also found that the average steady state temperature for the wire winding is 47.55°C and the predicted temperature from the formulated equation is 47.09°C with error less than 1 percent.

Abstract: This paper deals with the numerical investigation of transient behavior and thermal storage capability of a sensible heat storage unit. The former has a cubic configuration with embedded charging tubes; it is used to store solar energy with sand as a storage media. The system operates in the range of low temperature. To analyze their heat storage characteristics (including the bed temperature, energy stored rate, charging energy efficiency), a finite element based 2-D mathematical model has been developed using COMSOL Multiphysics. The results show that sand has an important thermal inertia. However, it was interesting to develop these storage systems in the region where both sand and solar energy were plentiful.