Sensitivity analysis of the proposed method for determining dynamic heat flux lost through the building envelope

2014 ◽  
Author(s):  
Agata Anna Swierc ◽  
Henryk Foit
Keyword(s):  
Heat Flux ◽  
Sensitivity Analysis ◽  
Building Envelope

Nanoparticle aggregation kinematics on the quadratic convective magnetohydrodynamic flow of nanomaterial past an inclined flat plate with sensitivity analysis

2021 ◽  
pp. 095440892110562
Author(s):  
AS Sabu ◽  
Joby Mackolil ◽  
B Mahanthesh ◽  
Alphonsa Mathew
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Sensitivity Analysis ◽  
Heat Transfer Coefficient ◽  
Heat Source ◽  
Transfer Coefficient ◽  
Flat Plate ◽  
Inclined Plate ◽  
The Impact ◽  
The Heat Transfer Coefficient

The study focuses on the aggregation kinematics in the quadratic convective magneto-hydrodynamics of ethylene glycol-titania ([Formula: see text]) nanofluid flowing through an inclined flat plate. The modified Krieger-Dougherty and Maxwell-Bruggeman models are used for the effective viscosity and thermal conductivity to account for the aggregation aspect. The effects of an exponential space-dependent heat source and thermal radiation are incorporated. The impact of pertinent parameters on the heat transfer coefficient is explored by using the Response Surface Methodology and Sensitivity Analysis. The effects of several parameters on the skin friction and heat transfer coefficient at the plate are displayed via surface graphs. The velocity and thermal profiles are compared for two physical scenarios: flow over a vertical plate and flow over an inclined plate. The nonlinear problem is solved using the Runge–Kutta-based shooting technique. It was found that the velocity profile significantly decreased as the inclination of the plate increased on the other hand the temperature profile improved. The heat transfer coefficient decreased due to the increase in the Hartmann number. The exponential heat source has a decreasing effect on the heat flux and the angle of inclination is more sensitive to the heat transfer coefficient than other variables. Further, when radiation is incremented, the sensitivity of the heat flux toward the inclination angle augments at the rate 0.5094% and the sensitivity toward the exponential heat source augments at the rate 0.0925%. In addition, 41.1388% decrement in wall shear stress is observed when the plate inclination is incremented from [Formula: see text] to [Formula: see text].

A transient method of measuring the thermal properties of rocks

Geophysics ◽  
1993 ◽  
Vol 58 (3) ◽  
pp. 357-365 ◽  
Author(s):  
Mike F. Middleton
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Sensitivity Analysis ◽  
Thermal Diffusivity ◽  
Sedimentary Basins ◽  
Constant Heat Flux ◽  
Transient Method ◽  
Constant Heat ◽  
Western Australian

The aim of the paper is to describe a new, rapid transient method for the determination of thermal diffusivity and thermal conductivity of rocks. The present transient method is based on the application of a constant heat flux to the top surface of a block of rock that is insulated on all other surfaces. Results of a sensitivity analysis of the method indicate that thermal diffusivity can be measured to a best accuracy of about 3 percent, and thermal conductivity of saturated rocks can be determined to a best accuracy of about 8 percent. The method provides estimates of thermal conductivity that are consistent with estimates made using the steady‐state divided‐bar apparatus. The method is applied to determine the thermal conductivity of a suite of rocks from western Australian sedimentary basins.

scholarly journals Sensitivity analysis of temperature in heated soft tissues with respect to time delays

2021 ◽  
Author(s):  
E. Majchrzak ◽  
G. Kałuża
Keyword(s):  
Heat Flux ◽  
Sensitivity Analysis ◽  
Soft Tissues ◽  
Initial Conditions ◽  
External Heat ◽  
Phase Lag ◽  
Thermalization Time ◽  
Temperature Changes ◽  
Tissue Region ◽  
External Heat Flux

AbstractAxisymmetric tissue region heated by an external heat flux is considered. The mathematical model is based on the dual-phase lag equation supplemented by appropriate boundary and initial conditions. This equation, in relation to the Pennes’ equation, has two additional parameters, namely the relaxation time and the thermalization time. The aim of this research is to estimate the temperature changes due to changes of these parameters. To achieve this, sensitivity analysis methods are used. The basic problem and additional ones related to the sensitivity functions are solved using the implicit scheme of the finite difference method. The performed computations show that the temperature changes caused by changes in the relaxation and thermalization times are larger for higher values of the external heat flux and shorter times of its action.

A Study of Cooling and Heating Energy Reduction Effects for Applying of Blind-Integrated Window System in Buildings

2014 ◽  
Vol 525 ◽  
pp. 392-396
Author(s):  
Bo Hye Choi ◽  
Gyeong Seok Choi ◽  
Jae Sik Kang ◽  
Seung Yeong Song
Keyword(s):  
Heat Flux ◽  
Surface Temperature ◽  
Outer Surface ◽  
Electricity Consumption ◽  
Building Envelope ◽  
Test Bed ◽  
Window System ◽  
Window Systems ◽  
Heating Load ◽  
Heating Energy Consumption

Recently, the window-to-wall ratio in the building envelope has gradually increased. In summer, as a result, cooling load significantly increases because of a large amount of sunlight coming through the windows. And in winter, thermal comfort can decrease at night because of heat loss and cold radiation which take place through the windows which have relatively low thermal resistance. To evaluate on characteristics of cooling and heating energy consumption under the blind-integrated window system which can fundamentally block this kind of cooling and heating load, this study has measured inner & outer surface temperature of glazing, electricity consumption and heat flux after installing the general and blind-integrated window systems in the test bed. According to the inner & outer surface temperature of glazing, the blind-integrated window system was 20.4°C while the general one was 14.4°C in summer. And in winter, the blind-integrated window system was 2.1°C while the general one was 0.8°C. Under the blind-integrated window system, in other words, electricity consumption was saved by up to 26% (about 11% daily), and heat flux decreased by approximately 34%. In addition, it's been confirmed that heater electricity consumption in winter could be saved up to 17%.

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