Thermochemical heat storage has obtained increasing attention in recent decades, which have been considered as a promising candidate to make long-term storage and long-distance transportation of thermal energy possible. The Ca(OH)2/CaO thermochemical heat storage system is thought of one of the most potential thermochemical processes for the storage of middle- and high-temperature thermal energy. In

This paper experimentally and numerically investigated the effects of impinging parameter variations on the performance of impinging-film cooling. The impinging parameters considered included jet inclination (30°, 45°, 60° and 90°), jet-to-slab spacing (1mm,1.5mm and 2mm) and jet hole diameter (d=1mm, 1.2mm and 1.6mm). The results show the jet inclination of 90° has higher cooling effectiveness compared

In this investigation, turbulent forced convection nanofluids flow with water as a base fluid, Al and Cu as particles of nano on an inclined forward-facing step are numerically studied. In a heated channel with different step, the angle of step and flow Reynolds number ranging were employed 20°≤θ≤80°, and 30000-100000, respectively. The concentrations of Al2O3 and CuO nanoparticle were considered 1%

A three-dimensional coupled heat transfer model is applied for numerical studies of turbulent flows and heat transfer of methane in variable cross-section cooling channels of LOX/Methane rocket engines at a supercritical pressure. The aim of the numerical simulation is to study the effects of different sudden contraction/sudden expansion area ratio on the cooling capacity of supercritical methane.

Unstable operations like temperature oscillation often occur in Loop Heat Pipes (LHPs) and therefore restrict their applications. Such instability issues are strongly related to the LHP structure, heat load, working fluid, filling ratio, gravity acceleration and other factors. The mechanism of temperature oscillation of LHP is studied both experimentally and theoretically by investigating the vapor-liquid

The thermal conductance in Nafion molecular chain is investigated performed by VASP, Phonopy and ShengBTE based on first principle calculation. Through the mechanical structural analysis and chemical bond analysis of crystal orbital overlap population, the strength of carbon-carbon bond, carbon-oxygen bond and carbon-sulfur bond is discussed. Combined with the pDOS (phonon density of state) analysis

Two-dimensional numerical simulations of underwater vapor bubble on a hot spot have been performed to investigate the thermocapillary-driven flow generated at the bubble interface and the accompanying flow near the contact line. With fixing the bubble diameter of 10 μm, several contact angle and hot-spot temperatures have been considered to discuss the flow characteristics relevant to a mechanism of

Flow and thermal characteristics of the Marangoni convection (thermo-capillary flow) around a micro-bubble are described in this study for the case of the bubble attached to the microchannel wall and the wall heated locally (hot spot applied). By providing heat source near the bubble and generating temperature gradient on the bubble surface Marangoni convection can be produced in the surrounding fluid

The thermal design of the various engineering applications plays a prominent role in deciding the overall efficiency of the system. Nowadays, nano fluids have attracted the interest from the researchers due to its excellent thermo physical properties. There were several researches emphasising the importance of two phase materials and nano fluids in the effective thermal design, but none have attempted

The icing on the aircraft induces a severe problem for the safety, and development of the simulation method has been required. In the present study, the effects of several icing conditions consisting of inflow velocity, liquid water content and angle of attack, on ice accretion on an airfoil are numerically investigated using a particle-based method. The computational target is NACA0012 airfoil with

The thermal and optical properties of layered structures of molybdenum disulphide (MoS2) were studied based on the first-principles. The photon density of states in various layered and bulk MoS2 shows a discontinuous band gap between about 7.0 and 8.0 THz. The specific heat variation with temperature and other thermodynamic properties like the Helmholtz free energy, entropy, and total energy are similar

In the present study, a thermochemical dissolution model based on the lattice Boltzmann method is proposed to investigate the reactive transport process involving the immiscible fluid flow, mass transport, heat transfer and dissolution. The flow of the two immiscible fluids, solute transport in the corresponding solvent and heat transfer are solved by the Shan-Chen multicomponent lattice Boltzmann

The condensation heat transfer characteristics of R290(propane) in horizontal smooth copper tubes and micro-fin copper tubes with outer diameter of 5mm and 7mm were investigated experimentally to study the condensation heat transfer strengthening characteristics. The enhancement factor Sf was introduced to characterize the degree of condensation heat transfer enhancement of R290 in micro-fin copper

The conventional fluids used for heat transfer can not provide the desired thermal performance due to their poor heat transfer characteristics. Disadvantages of the base fluids can be overcome by forming a suspension of nanoparticles with the base fluid. In this work, the effects of using dolomite/deionized water nanofluid on thermal performance of thermosyphon heat pipe were experimentally investigated

The purpose of this study is to explore the heat dissipation efficiency of piezoelectric fan with different type heat sinks by changing the piezoelectric fan height which is relative to three different heat sinks. This study use flow visualization technique with driven by 110V, 60Hz and fix the amplitude range of piezoelectric fan and distance (0.5 mm,1mm,2mm,3mm,4mm,5mm and 7mm) between blade tip

In this paper, the cavitating flow performance of a cavitation Venturi tube was studied to obtain the steady flow curve and predict the cavitation region based on the realizable k-ε turbulence model and Zwart（Zwart-Gerber-Belamri）cavitation model under the designated conditions. Venturi tubes with different throat diameters of 12mm, 10mm and 8mm were selected respectively, and the distance between

In this study, Eulerian multiphase model coupled with the Rensselaer Polytechnic Institute (RPI) wall boiling model and SST k-ω turbulence model is utilized to analyse the subcooled flow boiling heat transfer in a circular vertical boiler tube under constant wall heat flux boundary condition. The numerical model is validated with the experimental results reported in the published literatures. Further

In this work, we get the exact solution of a nonlinear model of the thermal shock problem of generalized thermoelastic half-space of temperature dependent materials. We considered two different cases of temperature dependent materials. Finite element analysis technique is used to get the numerical solutions. The results for the temperature increment, the displacement, and the stress distributions are

To further enhance pool boiling heat transfer , an new oscillation device was proposed. An oscillating plate was located over the heater surface with a vertical oscillation amplitude of 20mm and frequency of 6 HZ. Three N-type phosphorus-doped silicon chips were used as heater surfaces. One was smooth surface, and the other two were micro-pin-finned chips having fin thickness of 30 μm and fin height

This article presents an experimental study on the effect of temperature and solid volume fraction of nanoparticles on the dynamic viscosity for the CuO/EG-water nanofluid. nanoparticles with diameter of 40 nm are used in the present study to prepare nanofluid by two-step method. A “Brookfield viscometer” has been used to measure the dynamic viscosity of nanofluid with solid volume fraction up to 2%

Closed form solutions are presented for the steady magnetohydrodynamic (MHD) buoyancy-driven convection flow, heat and mass transfer from a semi-infinite vertical surface with wall transpiration, first order chemical reaction, viscous heating, Ohmic heating and magnetic induction effects. Magnetic Reynolds number is large enough to permit the inclusion of magnetic induction effects. The governing boundary

Boiling and condensation, a kind of convective heat transfer characterized by high heat fluxes, are widely encountered in many engineering applications. Fluids are the main heat carriers in heat transfer applications, and hence performance of a thermal system is remarkably linked with the working fluid's thermophysical properties. In thermal systems, nanofluids have been embarked upon to use as a working

Refrigerators are one of the most frequently used household devices; therefore, they represent an interesting subject for investigations. One of these research topics is the condensation problem in the gasket region. Despite the use of heaters in the refrigerator door, condensation on the surface of the gasket may still occur. Thus, there is a need for an improved gasket structure to overcome the condensation

A comprehensive thermodynamic analysis of a refrigeration system with an internal heat exchanger was reported for four various refrigerants as an alternative to R134a. The preferred refrigerants in this paper have zero ozone-depleting potential and fairly low global warming potential value compared with reference R134a. These refrigerants are from both the HC group (R290 and R600a) and the HFO group

In this study, the effects of malfunctions and problems occurring in the system components of air handling units, which are the main elements of the air conditioning system, on the energy consumption were investigated. Investigations were carried out in 10 air handling units located in 5 different shopping centers of Turkey. The malfunctions and problems that may occur in operation of air handling

One of the significant issues in energy conversion systems is efficient heat transfer which is generally done by heat exchangers (HEs). Different ways have been utilized to increase the performance of HEs. One of these ways for enhancing heat transfer rate is using a nanofluid. In this experimental work, the effect of utilizing Al2O3-SiO2/deionized water hybrid nanofluid at various particle ratios

Biopreservation is the science of extending the shelf life (storage time) of biological systems. The scientific field of biopreservation can be broadly classified into three distinct but interrelated research areas: Cryopreservation (storage by freezing), Desiccation (storage by drying) and Freeze-Drying (storage by freezing first and then sublimating the frozen water). Although, both freeze-frying