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Electronic components’ efficiency is the cornerstone of technology progress. The cooling process used for electronic components plays a main role in their performance. Embedded high-conductivity material and provided microchannel heat sink are two common cooling methods. The former is expensive to implement while the latter needs micro-pump, which consumes energy to circulate the flow. The aim of this study is providing a new configuration and method for improving the performance of electronic components.

To manage these challenges and improve the cooling efficiency, a novel method named Hybrid is presented here. Each method's performance has been investigated, and the results are widely compared with others. Considering the micro-pump power, the supply of the microchannel flow and the thermal conductivity ratio (thermal conductivity ratio is defined as the ratio of thermal conductivity of high thermal conductivity material to the thermal conductivity of base solid), the maximum disk temperature of each method was evaluated and compared to others.

The results indicated that the Hybrid method can reduce the maximum disk temperature up to 90 per cent compared to the embedded high thermal conductivity at the same thermal conductivity ratio. Moreover, the Hybrid method further reduces the maximum disk temperature up to 75 per cent compared to the microchannel, at equivalent power consumption.

The information in this research is presented in such a way that designers can choose the desired composition, the limited amount of consumed energy and the high temperature of the component. According to the study of radial-hybrid configuration, the different ratio of microchannel and materials with a high thermal conductivity coefficient in the constant cooling volume was investigated. The goal of the investigation was to decrease the maximum temperature of a plate on constant energy consumption. This aim has been obtained in the radial-hybrid configuration.

TURBINE disks of jet propulsion units operate under conditions of considerable complexity for which steam turbine practice and experience afford little assistance in matters of calculation and design.

The purpose of this paper is to report a study in which creative design concepts have been applied to automotive brake rotor design.

The literature review on creative design concepts and braking system scenario has been carried out. By studying the existing brake rotors and applying creative design concepts, modified rotor designs have been developed.

The experience gained out of the study indicated that braking efficiency and durability of the braking system can be significantly improved by the adoption of proposed designs.

The research has been carried out for an automotive passenger car. The findings of this research work could be extended to similar models of buses and trucks.

The usage of the proposed designs reduces the driver’s effort in braking and adds significantly to the life of the rotors.

A case study has been reported to indicate the application of creative design concepts for enhancing the efficiency of automotive braking system in cars.

The purpose of this paper is to present a method for thermal computations of power devices based on a coupling between thermal and pressure networks. The concept of the coupling as well as the solution procedure is explained. The included examples demonstrate that the new method can be efficiently used for design of transformers and other power devices.

The bidirectional propagation of temperature signal is introduced to the pressure network, which enables control of the power flow and a close coupling to the thermal network. The solution method is based on automatic splitting of the network definition (netlist) into two separate networks and iteratively solving the model using the Newton-Raphson approach as well as the adaptive relaxation enhanced by the direction change control.

The proposed approach offers reliable convergence behaviour even for models with unknown direction of the fluid flow (bidirectional flows). The accuracy is sufficient for engineering applications and comparable with the computational fluid dynamics method. The computation times in the range of milliseconds and seconds are attractive for using the method in engineering design tools.

The new method can be considered as a foundation for a consistent network modelling system of arbitrary thermodynamic problems including fluid flow. Such a modelling system can be used directly by device designers since the complexity of thermodynamic formulations is encapsulated in predefined network elements while the numerical solution is based on a standard network description and solvers (Spice).

AT the end of the war in Europe, Germany had two aircraft jet engines in operational use; the Junkers Jumo 004, which has already been described, and the BMW 003 which forms the subject of this article. Compared with the Junkers 004 the BMW engine can be described as having gone one stage further in the development of the axial compressor engine, but production figures were not as great as those of the Junkers. Several hundred had been built, mainly for the Heinkel He 162 Volksjäger—the high‐speed fighter with the engine mounted over the fuselage. The engines made in the 003 series are the 003‐A0, ‐Al, ‐A2, ‐E1 and ‐E2. These are all similar and have much the same performance. The latest in this series, the 003‐A2, is shown in fig. 1, and although production was planned on a large scale, only a few of this type were actually made.

NOW that the Air Ministry has released information on German power plants it is possible to give a detailed description and critical examination of the Jumo 004 jet engine. Most of the work of examination, including the repair and testing of an engine, was done some months preceding the final collapse of Germany. In this article it is hoped to supplement the information already given in the technical press.

The influence of buoyancy forces on oscillatory Marangoni flow in liquid bridges of different aspect ratio is investigated by three‐dimensional, time‐dependent numerical solutions and by laboratory experiments using a microscale apparatus and a thermographic visualisation system. Liquid bridges heated from above and from below are investigated. The numerical and experimental results show that for each aspect ratio and for both the heating conditions the onset of the Marangoni oscillatory flow is characterized by the appearance of a standing wave regime; after a certain time, a second transition to a travelling wave regime occurs. The three‐dimensional flow organization at the onset of instability is different according to whether the bridge is heated from above or from below. When the liquid bridge is heated from below, the critical Marangoni number is larger, the critical wave number (m) is smaller and the standing wave regime is more stable, compared with the case of the bridge heated from above. For the critical azimuthal wave number, two correlation laws are found as a function of the geometrical aspect ratio A.

This study aims to investigate numerically a thermomechanical behavior of disc brake using ANSYS 11.0 which applies the finite element method (FEM) to solve the transient thermal analysis and the static structural sequentially with the coupled method. Computational fluid dynamics analysis will help the authors in the calculation of the values of the heat transfer (h) that will be exploited in the transient evolution of the brake disc temperatures. Finally, the model resolution allows the authors to visualize other important results of this research such as the deformations and the Von Mises stress on the disc, as well as the contact pressure of the brake pads.

A transient finite element analysis (FEA) model was developed to calculate the temperature distribution of the brake rotor with respect to time. A steady-state CFD model was created to obtain convective heat transfer coefficients (HTC) that were used in the FE model. Because HTCs are dependent on temperature, it was necessary to couple the CFD and FEA solutions. A comparison was made between the temperature of full and ventilated brake disc showing the importance of cooling mode in the design of automobile discs.

These results are quite in good agreement with those found in reality in the brake discs in service and those that may be encountered before in literature research investigations of which these will be very useful for engineers and in the design field in the vehicle brake system industry. These are then compared to experimental results obtained from literatures that measured ventilated discs surface temperatures to validate the accuracy of the results from this simulation model.

The novelty of the work is the application of the FEM to solve the thermomechanical problem in which the results of this analysis are in accordance with the realized and in the current life of the braking phenomenon and in the brake discs in service thus with the thermal gradients and the phenomena of damage observed on used discs brake.

The braking system on motorcycles is of vital importance, taking into account that its operation is based on the friction between the surfaces in the contact that are found heat and, therefore, the brake liquid, the thermoelastic deformation on the contact surface, the degradation and failure of the material, as can be attributed to the safety of the occupants. The purpose of this paper is to perform mathematical calculations regarding the phenomena of the transfer of heat generated in the brake system.

Using SolidWorks simulation software, the geometric model of the three disc brakes of the different cylinders was carried out to identify the elements with the variations of the maximum temperature, and the verification with the calculations was made under ideal condition (80 Km/h and 12°C).

The results obtained show that with the mathematical calculations it was possible to validate the correct functioning of the braking system under different operating conditions, the systems that have higher capacity of displacement generate higher heat loss at higher speed so that their time of cooling according to Newton is major.

Through the analysis of finite elements, it was possible to identify that the braking system in severe working conditions is not overheated, assuring a natural convection cooling in approximately 12 min according to the mathematical calculations made.

The purpose of this study is to study the simultaneous effect of embedded reverting microchannels on the cooling performance and mechanical strength of the electronic pieces.

In this study, a new configuration of the microchannel heat sink was proposed based on the constructal theory to examine mechanical and thermal aspects. Initially, the thermal-mechanical behavior in the radial arrangement was analyzed, and then, by designing the first reverting channel, maximum temperature and maximum stress on the disk were decreased. After that, by creating second reverting channels, it has been shown that the piece is improved in terms of heat and mechanical strength.

Having placed the second reverting channel on the optimum location, the effect of creating the third reverting channel has been investigated. The study has shown that there is a close relationship between the maximum temperature and maximum stress in the disk as maximum temperature and maximum stress decrease in pieces with more uniform distribution channels.

The proposed structure has decreased the maximum temperature and maximum thermal stresses close to 35 and 50%, respectively, and also improved the mechanical strength, with and without thermal stresses, about 40 and 24%, respectively.