Unsteady temperature fields of evaporating water droplets exposed to conductive, convective and radiative heating

2018 ◽  
Vol 131 ◽  
pp. 340-355 ◽  
Author(s):  
G.V. Kuznetsov ◽  
M.V. Piskunov ◽  
R.S. Volkov ◽  
P.A. Strizhak
Keyword(s):  
Radiative Heating ◽  
Temperature Fields ◽  
Water Droplets ◽  
Unsteady Temperature

scholarly journals Gas-Vapor Mixture Temperature in the Near-Surface Layer of a Rapidly-Evaporating Water Droplet

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 803
Author(s):  
Antonov ◽  
Volkov ◽  
Strizhak
Keyword(s):  
High Temperature ◽  
Temperature Fields ◽  
Vapor Mixture ◽  
Water Droplets ◽  
Unsteady Temperature ◽  
Near Surface ◽  
Planar Laser ◽  
Steady Temperature Field ◽  
Experimental Values ◽  
High Temperature Gas

Mathematical modeling of the heat and mass transfer processes in the evaporating droplet–high-temperature gas medium system is difficult due to the need to describe the dynamics of the formation of the quasi-steady temperature field of evaporating droplets, as well as of a gas-vapor buffer layer around them and in their trace during evaporation in high-temperature gas flows. We used planar laser-induced fluorescence (PLIF) and laser-induced phosphorescence (LIP). The experiments were conducted with water droplets (initial radius 1–2 mm) heated in a hot air flow (temperature 20–500 °С, velocity 0.5–6 m/s). Unsteady temperature fields of water droplets and the gas-vapor mixture around them were recorded. High inhomogeneity of temperature fields under study has been validated. To determine the temperature in the so called dead zones, we solved the problem of heat transfer, in which the temperature in boundary conditions was set on the basis of experimental values.

scholarly journals The use of a solution of the inverse heat conduction problem to monitor thermal stresses

2019 ◽  
Vol 108 ◽  
pp. 01003
Author(s):  
Jan Taler ◽  
Piotr Dzierwa ◽  
Magdalena Jaremkiewicz ◽  
Dawid Taler ◽  
Karol Kaczmarski ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Power Plants ◽  
Thermal Stresses ◽  
Thermal Power ◽  
Temperature Fields ◽  
Thick Wall ◽  
Fluid Temperature ◽  
Unsteady Temperature

Thick-wall components of the thermal power unit limit maximum heating and cooling rates during start-up or shut-down of the unit. A method of monitoring the thermal stresses in thick-walled components of thermal power plants is presented. The time variations of the local heat transfer coefficient on the inner surface of the pressure component are determined based on the measurement of the wall temperature at one or six points respectively for one- and three-dimensional unsteady temperature fields in the component. The temperature sensors are located close to the internal surface of the component. A technique for measuring the fastchanging fluid temperature was developed. Thermal stresses in pressure components with complicated shapes can be computed using FEM (Finite Element Method) based on experimentally estimated fluid temperature and heat transfer coefficient

Displacing small particles by unsteady temperature fields

2005 ◽  
Vol 530 ◽  
pp. 125-134 ◽  
Author(s):  
EHUD YARIV
Keyword(s):  
Temperature Fields ◽  
Small Particles ◽  
Unsteady Temperature

scholarly journals SIMULATION OF A WATER CURTAIN APPLICATION TO PROTECT WORKERS FROM THERMAL INJURIES

2021 ◽  
pp. 28-35
Author(s):  
M. BILIAIEV ◽  
O. BERLOV ◽  
V. BILIAIEVA ◽  
O. VERGUN
Keyword(s):  
Mass Transfer ◽  
Numerical Model ◽  
Computational Experiment ◽  
Energy Equation ◽  
Computer Code ◽  
Temperature Fields ◽  
Water Droplets ◽  
Water Curtain ◽  
Heated Air ◽  
Potential Flow Model

Problem statement. The problem of evaluating the effectiveness of using the water curtain to reduce the risk of thermal injury to people in a fire is considered. The problem is to determine the temperature fields when supplying water for air cooling. The purpose of the article. Development of a numerical model for calculating the process of propagation of water droplets in the air, their evaporation to reduce the temperature of heated air due to fire. Methodology. For mathematical modeling of the process of propagation of water droplets in air, thermal air pollution, the convective-diffusion equation of mass transfer, the energy equation and the equation describing the motion of an ideal liquid (potential flow model) are used. The potential flow model allows you to quickly determine the field of air flow velocity in areas with a complex geometric shape. Implicit difference splitting schemes are used for numerical integration of the convective-diffusion mass transfer equation and the energy equation. Physical splitting of basic equations is used to construct a difference analogue of modeling equations. The Richardson method and the conditional approximation scheme are used to solve the aerodynamics problem of determining the velocity potential field and the components of the air velocity vector. An engineering method for calculating the process of evaporation of a drop of water based on Sreznevsky's law has been developed. Scientific novelty. An effective numerical model has been developed that allows the method of computational experiment to determine the efficiency of using the water curtain to reduce the level of thermal pollution of atmospheric air due to fire. The numerical model is based on the integration of the fundamental equations of aerodynamics, heat and mass transfer. The model takes into account the most significant physical factors that affect the process under study: the movement of heated air, the movement of water droplets in the air, evaporation of the droplet, and so on. Practical significance. Based on the built model, a computer code has been created that allows you to quickly determine the temperature fields in the air when using a water curtain. The numerical model will be useful when conducting computational experiments for the purpose of scientifically sound choice of the location of the water curtain in case of fire. Conclusions. A computer code has been created that allows a computational experiment to investigate the effectiveness of using a water curtain in a fire. The developed computer program can be implemented on low and medium power computers. The results of a computational experiment are presented.

Unsteady temperature fields of monoliths in catalytic converters

2004 ◽  
Vol 100 (1-3) ◽  
pp. 95-107 ◽  
Author(s):  
S SHUAI ◽  
J WANG
Keyword(s):  
Temperature Fields ◽  
Catalytic Converters ◽  
Unsteady Temperature

Temperature fields in a pipe wall in the case of radiative heating and a supercritical working-medium pressure

1974 ◽  
Vol 27 (2) ◽  
pp. 993-997
Author(s):  
V. B. Khabenskii ◽  
M. A. Kvetnyi ◽  
�. M. Tyntarev ◽  
R. I. Kalinin
Keyword(s):  
Pipe Wall ◽  
Radiative Heating ◽  
Temperature Fields ◽  
Medium Pressure ◽  
Working Medium

Method for calculating unsteady temperature fields and thermoelastic strain of plates

1976 ◽  
Vol 8 (1) ◽  
pp. 66-70
Author(s):  
A. L. Kvitka ◽  
A. S. Tsybenko ◽  
Yu. B. Gnuchii
Keyword(s):  
Temperature Fields ◽  
Unsteady Temperature
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