Radiative Transfer in Hartmann MHD Flow

1979 ◽  
Vol 101 (3) ◽  
pp. 502-506 ◽  
Author(s):  
T. F. Smith ◽  
P. H. Paul
Keyword(s):  
Radiative Transfer ◽  
Mhd Flow ◽  
Surface Heat ◽  
Heat Fluxes ◽  
Radiative Properties ◽  
Temperature Profiles ◽  
Gas Temperature ◽  
Real Gas ◽  
Gaseous Products ◽  
Transfer Term

The high temperatures and gaseous products resulting from combustion of hydrocarbon fuels in magnetohydrodynamic generators have provided an impetus to develop more accurate methods for prediction of gas temperature profiles and heat fluxes at the generator walls. One area where an improvement may be realized is in the evaluation of radiative transfer between the gas and surrounding walls. Analyses and results are presented to examine the importance of the radiative transfer term appearing in the gas energy balance for classical Hartmann MHD flow. Results for both real (nongray) and gray gas radiative properties are presented. Inclusion of radiation is found to increase the surface heat flux as well as to alter gas temperature profiles. Furthermore, real gas results differ significantly from those for a gray gas.

Combined Radiation—Convection for a Real Gas

1977 ◽  
Vol 99 (1) ◽  
pp. 60-65 ◽  
Author(s):  
N. K. Nakra ◽  
T. F. Smith
Keyword(s):  
Circular Tube ◽  
Tube Wall ◽  
Gas Absorption ◽  
Radiative Properties ◽  
Tube Length ◽  
Weighted Sum ◽  
Gas Temperature ◽  
Zone Method ◽  
Real Gas ◽  
Method Of Solution

A study of interaction of radiative transfer with convective transfer is presented for slug flow of an absorbing-emitting gas in a circular tube with an isothermal black wall. The zone method of solution is utilized to evaluate axial gas temperature and wall heat flux distributions using recently developed direct exchange areas for arbitrary zone width to radius ratio. Gas radiative properties are evaluated from the weighted sum of gray gases model with weighting factors and gray gas absorption coefficients applicable for an equimolal mixture of carbon dioxide and water vapor. Results are presented for several values of the governing parameters which are the Boltzmann and Stanton numbers, inlet gas and tube wall temperatures, as well as tube length to diameter ratio. Effects of cooling and heating of the gas are examined.

Trends of land surface heat fluxes on the Tibetan Plateau from 2001 to 2012

2017 ◽  
Vol 37 (14) ◽  
pp. 4757-4767 ◽  
Author(s):  
Cunbo Han ◽  
Yaoming Ma ◽  
Xuelong Chen ◽  
Zhongbo Su
Keyword(s):  
Tibetan Plateau ◽  
Land Surface ◽  
Surface Heat ◽  
Heat Fluxes ◽  
The Tibetan Plateau ◽  
Surface Heat Fluxes ◽  
Land Surface Heat Fluxes

On the Hyperbolicity of the Bulk Air–Sea Heat Flux Functions: Insights into the Efficiency of Air–Sea Moisture Disequilibrium for Tropical Cyclone Intensification

2021 ◽  
Vol 149 (5) ◽  
pp. 1517-1534
Author(s):  
Benjamin Jaimes de la Cruz ◽  
Lynn K. Shay ◽  
Joshua B. Wadler ◽  
Johna E. Rudzin
Keyword(s):  
Tropical Cyclone ◽  
Surface Wind ◽  
Heat Content ◽  
Surface Heat ◽  
Heat Fluxes ◽  
Ocean Heat Uptake ◽  
Surface Heat Fluxes ◽  
Heat Uptake ◽  
Moisture Fluxes ◽  
New Perspective

AbstractSea-to-air heat fluxes are the energy source for tropical cyclone (TC) development and maintenance. In the bulk aerodynamic formulas, these fluxes are a function of surface wind speed U10 and air–sea temperature and moisture disequilibrium (ΔT and Δq, respectively). Although many studies have explained TC intensification through the mutual dependence between increasing U10 and increasing sea-to-air heat fluxes, recent studies have found that TC intensification can occur through deep convective vortex structures that obtain their local buoyancy from sea-to-air moisture fluxes, even under conditions of relatively low wind. Herein, a new perspective on the bulk aerodynamic formulas is introduced to evaluate the relative contribution of wind-driven (U10) and thermodynamically driven (ΔT and Δq) ocean heat uptake. Previously unnoticed salient properties of these formulas, reported here, are as follows: 1) these functions are hyperbolic and 2) increasing Δq is an efficient mechanism for enhancing the fluxes. This new perspective was used to investigate surface heat fluxes in six TCs during phases of steady-state intensity (SS), slow intensification (SI), and rapid intensification (RI). A capping of wind-driven heat uptake was found during periods of SS, SI, and RI. Compensation by larger values of Δq > 5 g kg−1 at moderate values of U10 led to intense inner-core moisture fluxes of greater than 600 W m−2 during RI. Peak values in Δq preferentially occurred over oceanic regimes with higher sea surface temperature (SST) and upper-ocean heat content. Thus, increasing SST and Δq is a very effective way to increase surface heat fluxes—this can easily be achieved as a TC moves over deeper warm oceanic regimes.

Boundary Surface Heat Fluxes in a Square Enclosure with an Embedded Design Element

2010 ◽  
Vol 24 (4) ◽  
pp. 845-849 ◽  
Author(s):  
M. Ajith ◽  
Ranjan Das ◽  
Ramgopal Uppaluri ◽  
Subhash C. Mishra
Keyword(s):  
Boundary Surface ◽  
Surface Heat ◽  
Heat Fluxes ◽  
Design Element ◽  
Surface Heat Fluxes ◽  
Square Enclosure ◽  
Embedded Design

scholarly journals Simulation of surface heat fluxes of Typhoon Songda (Chedeng) 2011 using WRF-ARW model

2017 ◽  
Vol 56 ◽  
pp. 012008
Author(s):  
Muhammad ◽  
R I Lestari ◽  
F Mulia ◽  
Y Ilhamsyah ◽  
Z Jalil ◽  
...  
Keyword(s):  
Surface Heat ◽  
Heat Fluxes ◽  
Surface Heat Fluxes ◽  
Arw Model
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