scholarly journals Heat flux from stagnation-point hydrogen-methane-air flames: experiment and modelling

2014 ◽  
Author(s):  
M. S. Elmnefi
Keyword(s):  
Heat Flux ◽  
Stagnation Point

Boiling Heat Transfer Characteristics of Rotary Hollow Cylinders with In-Line and Staggered Multiple Arrays of Water Jets

2021 ◽  
Author(s):  
Mohammad Jahedi ◽  
Bahram Moshfegh
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Stagnation Point ◽  
Surface Heat Flux ◽  
Surface Heat ◽  
Maximum Heat ◽  
Water Jets ◽  
Maximum Heat Flux ◽  
Inner Surface ◽  
Hollow Cylinders

Abstract Transient heat transfer studies of quenching rotary hollow cylinders with in-line and staggered multiple arrays of jets have been carried out experimentally. The study involves three hollow cylinders (Do/d = 12 to 24) with rotation speed 10 to 50 rpm, quenched by subcooled water jets (ΔTsub=50-80 K) with jet flow rate 2.7 to 10.9 L/min. The increase in area-averaged and maximum heat flux over quenching surface (Af) has been observed in the studied multiple arrays with constant Qtotal compared to previous studies. Investigation of radial temperature distribution at stagnation point of jet reveals that the footprint of configuration of 4-row array is highlighted in radial distances near the outer surface and vanishes further down toward the inner surface. The influence of the main quenching parameters on local average surface heat flux at stagnation point is addressed in all the boiling regimes where the result indicates jet flow rate provides strongest effect in all the boiling regimes. Effectiveness of magnitude of maximum heat flux in the boiling curve for the studied parameters is reported. The result of spatial and temporal heat flux by radial conduction in the solid presents projection depth of cyclic variation of surface heat flux in the radial axis as it disappears near inner surface of hollow cylinder. In addition, correlations are proposed for area-averaged Nusselt number as well as average and maximum local heat flux at stagnation point of jet for the in-line and staggered multiple arrays.

scholarly journals Buoyancy effects in stagnation-point flow of Maxwell fluid utilizing non-Fourier heat flux approach

PLoS ONE ◽  
2018 ◽  
Vol 13 (5) ◽  
pp. e0192685 ◽  
Author(s):  
Ammar Mushtaq ◽  
Meraj Mustafa ◽  
Tasawer Hayat ◽  
Ahmed Alsaedi
Keyword(s):  
Heat Flux ◽  
Stagnation Point ◽  
Maxwell Fluid ◽  
Stagnation Point Flow

scholarly journals Axisymmetric stagnation-point flow and heat transfer of nanofluid impinging on a cylinder with constant wall heat flux

2019 ◽  
Vol 23 (5 Part B) ◽  
pp. 3153-3164 ◽  
Author(s):  
Hamid Mohammadiun ◽  
Vahid Amerian ◽  
Mohammad Mohammadiun ◽  
Iman Khazaee ◽  
Mohsen Darabi ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Velocity Field ◽  
Stagnation Point ◽  
Base Fluid ◽  
Fluid Velocity ◽  
Wall Heat Flux ◽  
Flow And Heat Transfer ◽  
Constant Wall Heat Flux ◽  
Fluid Velocity Field

The steady-state, viscous flow and heat transfer of nanofluid in the vicinity of an axisymmetric stagnation point of a stationary cylinder with constant wall heat flux is investigated. The impinging free-stream is steady and with a constant strain rate, k ?. Exact solution of the Navier-Stokes equations and energy equation are derived in this problem. A reduction of these equations is obtained by use of appropriate transformations introduced in this research. The general self-similar solution is obtained when the wall heat flux of the cylinder is constant. All the previous solutions are presented for Reynolds number Re = k ?a2/2n f ranging from 0.1 to 1000, selected values of heat flux and selected values of particle fractions where a is cylinder radius and n f is kinematic viscosity of the base fluid. For all Reynolds numbers, as the particle fraction increases, the depth of diffusion of the fluid velocity field in radial direction, the depth of the diffusion of the fluid velocity field in z-direction, shear-stresses and pressure function decreases. However, the depth of diffusion of the thermal boundary-layer increases. It is clear by adding nanoparticles to the base fluid there is a significant enhancement in Nusselt number and heat transfer.

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