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The strong coupling heat transfer between subassemblies and inter-wrapper gaps is closely related to the safety of the sodium-cooled fast reactor (SFR). Therefore, it is very important to carry out a detailed thermal hydraulic analysis of the core. In this paper, the inter-wrapper channel is modeled using the subchannel analysis method. A core thermal-hydraulic analysis code SACOS-Na (Subchannel Analysis Code Of Safety for SFR) is developed by using SIMPLE algorithm. For the subassembly module, a total of three experiments, including ORNL 19-pin experiment, TOSHIBA 37-pin experiment and KNS 37-pin experiment, are adopted to demonstrate the feasibility of the mathematical and physical models and numerical algorithms of the SACOS-Na as well as the rationality of the selected auxiliary models. For the inter-wrapper gap module, WEISS 2-subassembly experiment and CCTL-CFR 3-subassembly experiment are used to verify not only the simulation capability for backflow and strong inter-subassembly heat transfer, but also the heat structure model and the subchannel modeling approach on inter-wrapper gaps. In addition, the prediction accuracy of SACOS-Na has reached the advanced international level by comparing with the worldwide well-known core thermal hydraulic analysis codes. • The subchannel modeling method is adopted to build the mesh for inter-wrapper channels. • The SIMPLE algorithm is used to solve the problems of the reverse flow and inter-subassembly heat transfer occurred in SFRs. • The universal core thermal-hydraulic analysis code SACOS-Na for SFRs is developed. • The accuracy and reliability of the SACOS-Na are discussed from all aspects. [ABSTRACT FROM AUTHOR]

In this paper, a numerical model describing the heat transfer and air flow inside and outside the casing of the permanent magnet brushless direct current (PM BLDC) motor is presented. In the model, a conjugate heat transfer including the heat conduction with heat sources in windings, magnets, bearings, natural and forced convection and radiation phenomena within internal and external air domain were analysed. The complex geometrical model included windings, a magnet circuit, a rotor with neodymium magnets, a PCB electronic plate, plastic covers, internal air between solid parts as well as a portion of the external air. The validation process of the developed model was realised on the basis of the velocity and temperature fields. The experimental data were recorded by 7 constant temperature anemometers at 4 levels above the motor housing, Laser Doppler Anemometry sensors in two axes inside the rear portion of the motor and 25 thermocouples fixed inside and outside the motor. The experimental and numerical tests were performed for 4 motor loadings and 3 rotational speeds. The average temperature error for the internal point was of 9 K, while that of the external points was of 2 K. The velocity field was very well predicted close to the housing wall in terms of horizontal and vertical components. A slightly worse agreement was found for the vertical component, especially in the vicinity of the shaft. The results were consistent for all the considered motor loadings and rotational speeds. [ABSTRACT FROM AUTHOR]

In this paper we perform predictive simulations of liquid pool fires in mechanically ventilated compartments. We show that steady state burning rates are accurately predicted using a detailed model for the liquid phase heat transfer. The effect of lowered oxygen vitiation on the burning rate of pool fires is correctly captured. Simulations were done using the Fire Dynamics Simulator and the experiments considered were conducted in the OECD PRISME project. The main difference between the present study and previous simulation studies is the use of a detailed liquid evaporation model and the direct calculation of the vitiation and thermal environment interactions through the CFD solver. [ABSTRACT FROM AUTHOR]

Fire fighting is a hazardous occupation and the use of good quality thermal protective clothing is vital in the prevention of heat related injuries. Protective fire fighting clothing is generally chosen for its thermal and fire resistant properties, while also considering the weight, bulk and ease of movement of the suit. This research proposes incorporating a phase change material (PCM) into the fabric of the fire fighting suit in conjunction with air gaps to increase the thermal protection. A mathematical model of heat transport through a suit that contains PCMs and air gaps is presented. We investigate the distribution of temperature within the fabric during exposure to different fire situations. To assess the protective nature of the clothing, we model the skin as three layers with differing thermal properties (the epidermis, dermis and the subcutaneous layer) and examine the temperatures within the skin. The model can then be used to determine if the inclusion of a PCM layer would provide increased thermal protection to the fire fighter. Our earlier research has indicated that the most effective position for a PCM layer is near the outside of the suit. This paper will focus on the effect of the PCM layer in combination with air layers in the suit. Our results clearly show that an additional air layer increases the protection provided by the suit. This benefit comes without significantly increasing the overall weight of the suit. [ABSTRACT FROM AUTHOR]

Energy conversion devices undergo thermal loading during their operation as a result of inefficiencies in the energy conversion process. This will eventually lead to degradation and possible failure of the device if the heat generated is not properly managed. The ability to accurately predict the thermal behavior of such a device during the initial developmental stage is an important requirement. However, accurate predictions of critical temperature is challenging due to the variation of heat transfer parameters from one device to another. The ability to determine the model parameters is key to accurately representing the heat transfer in such a device. This paper presents the use of an inverse identification technique to estimate the model parameters of an energy conversion device designed for vehicular applications. To simulate the imperfect contact and the presence of insulating materials in the permanent magnet electric machine, thin material are introduced at the component interface of the numerical model. The proposed inverse identification method is used to estimate the equivalent thermal conductance of the thin material. In addition, the electromagnetic losses generated in the permanent magnet is also derived indirectly from the temperature measurement using the same method. With the thermal properties and input parameters of the numerical model obtained from the inverse identification method, the critical temperature of the device can be predicted more accurately. The deviation between the maximum measured and predicted winding temperature is less than 2.4%. [ABSTRACT FROM AUTHOR]