Numerical Analysis of Heat Loss Effects on the Smoldering Combustion of a Thin Solid in a Narrow Channel

2017 ◽  
Vol 50 (7) ◽  
pp. 535-541 ◽  
Author(s):  
Hiroyuki Iizuka ◽  
Kazunori Kuwana ◽  
Genichiro Kushida
Keyword(s):  
Numerical Analysis ◽  
Heat Loss ◽  
Narrow Channel ◽  
Smoldering Combustion

Numerical analysis of a hybrid tubular and cavity air receiver for solar thermal applications

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sayuj Sasidharan ◽  
Pradip Dutta
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Analysis ◽  
Heat Loss ◽  
Solar Thermal ◽  
Heat Transfer Analysis ◽  
Receiver Design ◽  
Radiation Emission ◽  
Content Type ◽  
Thermal Receiver

Purpose This paper aims to deal with characterisation of the thermal performance of a hybrid tubular and cavity solar thermal receiver. Design/methodology/approach The coupled optical-flow-thermal analysis is carried out on the proposed receiver design. Modelling is performed in two and three dimensions for estimating heat loss by natural convection for an upward-facing cavity. Heat loss obtained in two dimensions by solving coupled continuity, momentum and energy equation inside the cavity domain is compared with the loss obtained using an established Nusselt number correlation for realistic receiver performance prediction. Findings It is found that radiation emission from a heated cavity wall to the ambient is the dominant mode of heat loss from the receiver. The findings recommend that fluid flow path must be designed adjacent to the surface exposed to irradiation of concentrated flux to limit conduction heat loss. Research limitations/implications On-sun experimental tests need to be performed to validate the numerical study. Practical implications Numerical analysis of receivers provides guidelines for effective and efficient solar thermal receiver design. Social implications Pressurised air receivers designed from this method can be integrated with Brayton cycles using air or supercritical carbon-dioxide to run a turbine generating electricity using a solar heat source. Originality/value The present paper proposes a novel method for coupling the flux map from ray-tracing analysis and using it as a heat flux boundary condition for performing coupled flow and heat transfer analysis. This is achieved using affine transformation implemented using extrusion coupling tool from COMSOL Multiphysics software package. Cavity surface natural convection heat transfer coefficient is obtained locally based on the surface temperature distribution.

Numerical Analysis of Multi-Layer Continuous Diffusion Furnace Door Gas Curtain

2013 ◽  
Vol 367 ◽  
pp. 462-465
Author(s):  
Sheng Cai Zhang ◽  
Gui Qin Li ◽  
Li Xin Lu ◽  
Peter Mitrouchev ◽  
Cheng Gang Wang
Keyword(s):  
Numerical Analysis ◽  
Heat Loss ◽  
Thermal Load ◽  
Gas Flow ◽  
Time Varying ◽  
Main Aspect ◽  
Temperature Zone ◽  
Furnace Temperature ◽  
Air Curtain ◽  
Reduce Heat Loss

Thermal load oozing out through the door is the main aspect of the temperature zone heat loss of continuous diffusion furnace. In this paper, multi-layer gas curtain is designed to seal the furnace door in order to reduce heat loss and ensure furnace temperature to meet requirements in regulation. The unsteady flow is presented to better reflect complex time-varying velocity and temperature of curtain gas. Flow and temperature field of continuous diffusion door with multi-layer air curtain are numerically analyzed by Renault model and experimentally tested. And the influence parameters are tuned and optimized based on the theoretic numerical analysis and experiment results.

The Flow Phenomena and the Non-Uniform Filling of the Unvulcanized Rubber in Process of Filling

2009 ◽  
Author(s):  
Shintarou Sakai ◽  
Toru Shigemitsu ◽  
Junichiro Fukutomi ◽  
Tsukasa Matsuoka
Keyword(s):  
Numerical Analysis ◽  
Narrow Channel ◽  
Numerical Results ◽  
Flow Conditions ◽  
Flow Phenomena ◽  
Rubber Product ◽  
Vulcanization Process ◽  
Filling State ◽  
Optimum Flow ◽  
Good Agreement

Rubber products like oil seal are produced by vulcanization molding and the vulcanization molding of rubber product is performed by past experience, trial and error. It is important issues to decrease the product cost, reduce defective products and solve the environmental problems by saving natural resources. If the vulcanization moldings of rubber products are reappeared by computer simulation, it is very useful and it could contribute to solve the above problems. In order to reduce surplus rubber and defective products, numerical analysis of flow phenomena of unvulcanized rubber was performed using commercial software FIDAP. In several types of rubber mold model, the numerical analysis was conducted taken the characteristic of visco-elasticity fluid obtained by an experiment without considering the effect of heat. And experiments were conducted for the comparison of numerical results and actual phenomena. In the experiment, vulcanization process was stopped by arbitrary interval. Then the filling state and the shape of the rubber at each interval are observed in numerical and experiment results. The results showed that the filling state of numerical results represented good agreement with the experimental results. And it was clarified from the numerical analysis that shear stress increased when the unvulcanized rubber flowed in a narrow channel and there was the relation between pressure and velocity. In the present paper, the flow phenomena under the condition of the compression molding are shown and the optimum flow conditions are discussed from the numerical results. Furthermore mechanism of occurrence of defective products is considered with the experimental and the numerical results.

scholarly journals Numerical analysis of the heat loss of stop valves of heat networks

2017 ◽  
Vol 110 ◽  
pp. 01067
Author(s):  
Vyacheslav Polovnikov ◽  
Anatolij Vergun ◽  
Vasilij Sergeenko
Keyword(s):  
Numerical Analysis ◽  
Heat Loss ◽  
Heat Networks

scholarly journals Numerical Analysis of Influence of Engineering Construction in the Area of Placing Fuel Storage Tanks on their Heat Loss

2016 ◽  
Vol 72 ◽  
pp. 01133
Author(s):  
V. Yu. Polovnikov ◽  
F. T. Makhsutbek ◽  
Zh. F. Ozhikenova ◽  
I. K. Zharova
Keyword(s):  
Numerical Analysis ◽  
Heat Loss ◽  
Storage Tanks ◽  
Engineering Construction ◽  
Fuel Storage
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