Some research in the area of the determination of nonsteady heat fluxes

1977 ◽  
Vol 33 (6) ◽  
pp. 1475-1480
Author(s):  
G. A. Surkov ◽  
F. B. Yurevich ◽  
S. D. Skakun
Keyword(s):  
Heat Fluxes ◽  
Nonsteady Heat

Simultaneous Determination of Steady Temperatures and Heat Fluxes on Surfaces of Three Dimensional Objects Using FEM

2001 ◽  
Author(s):  
Brian H. Dennis ◽  
George S. Dulikravich
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Heat Conduction ◽  
Three Dimensional ◽  
Heat Fluxes ◽  
Multiply Connected ◽  
Three Dimensional Objects ◽  
Solid Objects ◽  
System Solution

Abstract A finite element method (FEM) formulation is presented for the prediction of unknown steady boundary conditions in heat conduction on multiply connected three-dimensional solid objects. The present FEM formulation is capable of determining temperatures and heat fluxes on the boundaries where such quantities are unknown or inaccessible, provided such quantities are sufficiently over-specified on other boundaries. Details of the discretization, linear system solution techniques, regularization, and sample results for 3-D problems are presented.

scholarly journals The Surface Energy Balance System (SEBS) for estimation of turbulent heat fluxes

2002 ◽  
Vol 6 (1) ◽  
pp. 85-100 ◽  
Author(s):  
Z. Su
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Heat Fluxes ◽  
Physical Parameters ◽  
Turbulent Heat ◽  
Evaporative Fraction ◽  
Balance System ◽  
Turbulent Heat Fluxes

Abstract. A Surface Energy Balance System (SEBS) is proposed for the estimation of atmospheric turbulent fluxes and evaporative fraction using satellite earth observation data, in combination with meteorological information at proper scales. SEBS consists of: a set of tools for the determination of the land surface physical parameters, such as albedo, emissivity, temperature, vegetation coverage etc., from spectral reflectance and radiance measurements; a model for the determination of the roughness length for heat transfer; and a new formulation for the determination of the evaporative fraction on the basis of energy balance at limiting cases. Four experimental data sets are used to assess the reliabilities of SEBS. Based on these case studies, SEBS has proven to be capable to estimate turbulent heat fluxes and evaporative fraction at various scales with acceptable accuracy. The uncertainties in the estimated heat fluxes are comparable to in-situ measurement uncertainties. Keywords: Surface energy balance, turbulent heat flux, evaporation, remote sensing

Conjugate Flow and Heat Transfer Investigation of a Turbo Charger: Part I — Numerical Results

2003 ◽  
Author(s):  
Dieter Bohn ◽  
Tom Heuer ◽  
Karsten Kusterer
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Heat Fluxes ◽  
Inlet Temperature ◽  
Three Dimensional Model ◽  
Flow And Heat Transfer ◽  
Turbine Inlet ◽  
Turbo Charger ◽  
Conjugate Calculation

In this paper a three-dimensional conjugate calculation has been performed for a passenger car turbo charger. The scope of this work is to investigate the heat fluxes in the radial compressor which can be strongly influenced by the hot turbine. As a result of this, the compressor efficiency may deteriorate. Consequently, the heat fluxes have to be taken into account for the determination of the efficiency. To overcome this problem a complex three-dimensional model has been developed. It contains the compressor, the oil cooled center housing, and the turbine. 12 operating points have been numerically simulated composed of three different turbine inlet temperatures and four different mass flows. The boundary conditions for the flow and for the outer casing were derived from experimental test data (part II of the paper). Resulting from these conjugate calculations various one-dimensional calculation specifications have been developed. They describe the heat transfer phenomena inside the compressor with the help of a Nusselt number which is a function of an artificial Reynolds number and the turbine inlet temperature.

Determination of the characteristics of nonsteady heat exchange in one disperse reactive system

1978 ◽  
Vol 35 (6) ◽  
pp. 1429-1435
Author(s):  
A. M. Grishin ◽  
G. S. Loskutov ◽  
T. S. Sandrykina
Keyword(s):  
Heat Exchange ◽  
Reactive System ◽  
Nonsteady Heat

Identification of nonsteady heat fluxes by using the output signals of thin-membrane gardon-type sensors

1993 ◽  
Vol 65 (6) ◽  
pp. 1223-1229
Author(s):  
A. M. Vorob'ev ◽  
V. I. Zhuk ◽  
V. P. Sizov ◽  
D. N. Chubarov
Keyword(s):  
Heat Fluxes ◽  
Thin Membrane ◽  
Nonsteady Heat

Determination of Radiative Fluxes in an Absorbing, Emitting, and Scattering Vapor Formed by Laser Irradiation

1991 ◽  
Vol 113 (4) ◽  
pp. 939-945 ◽  
Author(s):  
P. Erpelding ◽  
A. Minardi ◽  
P. J. Bishop
Keyword(s):  
Radiative Heat ◽  
Radiative Transfer Equation ◽  
Heat Fluxes ◽  
Radiative Properties ◽  
Medium Temperature ◽  
Radiative Fluxes ◽  
Factors Affecting ◽  
Axial Heat ◽  
Significant Factors

A two-dimensional computer model is developed to determine the radiative heat flux distributions within the vapor formed above a metal target irradiated by a laser beam. An axisymmetric cylindrical enclosure containing a radiatively participating medium is considered. Scattering is assumed to be isotropic and allowances are made for variation of the radiative properties of the medium and boundaries. The P-1 and P-3 spherical harmonics approximations are used to solve the integro-differential radiative transfer equation. The resulting equations are then solved for the radial and axial heat fluxes using a finite-difference algorithm. The most significant factors affecting the results obtained from both the P-1 and P-3 approximations were the optical thickness of the medium and the type of laser profile incident upon the medium. Using different wall reflectivities and scattering albedos had a smaller effect. Changing the medium temperature had an insignificant effect as long as medium temperatures were below 20,000 K.

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