Electrohydrodynamic (EHD) has been applied in many areas, such as EHD atomization, EHD enhanced heat transfer, EHD pump, electrospray nanotechnology, etc. EHD atomization is a promising materials deposition technique as it allows uniform and regular deposition, and offers a range of other advantages, such as low cost compared with other current techniques, easy set-up, high deposition rate, and ambient temperature. Simulation is carried out using ANSYS FLUENT system. The approach in this work was to simultaneously solve the coupled (EHD) and electrostatic equations. The fields of velocities and pressure, as well as electric characteristics of EHD flows, are calculated. The model does not include a droplet break-up model.

Radiation heat transfer coefficient of the human body is one of the most important factors in the field of human skin health. In this paper, the radiation coefficient of the body is calculated by considering external heat radiation of body with the infinite surrounding. At first a human body is designed, and then analysis is done on it. Two segments are assumed for human body (standing and supine). In these segments hands and feet are supposed to be totally open and stretched. In standing segment, soles and in supine segment, the entire back of the body are in contact with the ground and so don’t have heat transfer. The calculation of the results is done by weighted area average method. Radiation coefficient and radiation heat flux are calculated in various emissivity. Because of existence of air around the body in reality, the convection heat transfer is also assumed for human body. Finally two formulas are reported for these segments.

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This study presents a detailed dynamic modelling and generic simulation method of an oscillating diaphragm compressor for chemisorption energy technology applications. The geometric models of the compressor were developed step by step, including the diaphragm movement, compressor dimensions, chamber areas and volumes and so on. The detailed mathematical model representing the geometry and kinematics of the diaphragm compressor was combined with the motion equation, heat transfer equation and energy balance equation to complete the compressor modelling. This combination enables the novel compressor model to simultaneously handle the simulation of momentum and energy balance of the diagram compressor. Furthermore, an experimental apparatus was set up to investigate and validate the present modelling and the simulation method. The performance of the compressor was experimentally evaluated in terms of the mass flow rate of the compressor at various compression ratios. Additionally, the effects of different parameters such as the inlet temperature and ambient temperature at various compressor ratios on the compressor performance were investigated. It was found reducing the inlet temperature from 40 to 5 ∘C at a constant pressure results in the enhancement of the compressor flow rate up to 14.7%. The compressor model proposed and developed in this study is shown to be not only able to accurately deal with the complexity of the dynamic behaviour of the compressor working flow but is also capable of effectively representing diaphragm compressors for analysis and optimisation purposes in various applications.

Solar cooling technologies have the potential to improve crop and vaccine supply chain management in areas with unreliable access to an electricity distribution network. The diffusion absorption refrigeration (DAR) cycle is a technology of interest for cooling in rural areas and developing countries due to its low capital cost, low maintenance requirements, and unique design in which the requirement for electrically-driven components are fully omitted. The main feature of DAR systems is a thermally driven bubble pump that is used to circulate the refrigerant and absorbent fluid components around the system. In this paper, we present results from a laboratory DAR system operating over a range of pressures and heat input rates with ammonia-water-hydrogen as the working fluid. By reducing the system pressure from 21 bar to 14 bar, a 17% increase in maximum coefficient of performance (COP) is reported, and the system start-up time is reduced by up to 58%. The results are used to calibrate a thermal model of a solar-DAR system, which is then used to determine the optimal system pressure and solar collector array configuration for summer operation in the location of Chennai, India.Recent research has considered how the DAR cycle can be adapted for use in a lower temperature range with solar thermal collectors. Approaches considered include the use of alternative working fluids (Zohar et al. 2009, Ben Ezzine et al. 2010, Acuña et al., 2013 and the configuration of the generator and bubble pump (Zohar et al. 2008, Damak et al., 2010. The UK company Solar-Polar has recently developed a solar-DAR system for use in rural cold chain applications. A field-test of the system is currently in preparation at Anna University in Chennai, India (see Fig. 2), where fifteen modular roof-top units will be used to provide cooling to a 34 m 3 insulated cold store. Each unit provides a nominal 60-70 W of cooling from a 0.72 m 2 array of solar heat pipe collectors. A one-year monitoring study will be undertaken in order to assess the seasonal performance of the system.