scholarly journals Analyzing impact of sensor coupling on measurement representativeness of wall surface temperature

2021 ◽  
Author(s):  
Sadaf Mansour
Keyword(s):  
Surface Temperature ◽  
Temperature Difference ◽  
Indoor Air ◽  
Internal Surface ◽  
Thermal Coupling ◽  
Wall Surface ◽  
Surrounding Environment ◽  
Wall Assembly ◽  
The Impact ◽  
Wall Surface Temperature

Poor thermal-coupling between sensor and surface is one of the most important factors causing inaccuracy in measurement. Different methods had been suggested by scientists to solve this issue. Embedding the sensor into an object was one of these methods. The goal of these simulations was to assess the impact of sensor coupling on measurement representativeness of wall surface temperature. For this purpose, a cylindrically-shaped sensor was embedded into the internal surface of the wall assembly. The levels of tightness varied from 10% to 90%, which corresponded respectively from very loose to very tight conditions. Also, in this process the impact of other factors such size and materiality of the sensors’ accuracy were evaluated and discussed briefly. In this study, the results proved that as the sensor decoupled more from the surrounding environment, more accurate data was generated from it. Also, the results from the simulations signified the importance of the temperature difference between the wall surface and the indoor air temperature. The temperature difference had a direct relationship with sensor accuracy and measurement representativeness, where smaller temperature difference was associated with higher accuracy.

scholarly journals Analyzing impact of sensor coupling on measurement representativeness of wall surface temperature

2021 ◽  
Author(s):  
Sadaf Mansour
Keyword(s):  
Surface Temperature ◽  
Temperature Difference ◽  
Indoor Air ◽  
Internal Surface ◽  
Thermal Coupling ◽  
Wall Surface ◽  
Surrounding Environment ◽  
Wall Assembly ◽  
The Impact ◽  
Wall Surface Temperature

Poor thermal-coupling between sensor and surface is one of the most important factors causing inaccuracy in measurement. Different methods had been suggested by scientists to solve this issue. Embedding the sensor into an object was one of these methods. The goal of these simulations was to assess the impact of sensor coupling on measurement representativeness of wall surface temperature. For this purpose, a cylindrically-shaped sensor was embedded into the internal surface of the wall assembly. The levels of tightness varied from 10% to 90%, which corresponded respectively from very loose to very tight conditions. Also, in this process the impact of other factors such size and materiality of the sensors’ accuracy were evaluated and discussed briefly. In this study, the results proved that as the sensor decoupled more from the surrounding environment, more accurate data was generated from it. Also, the results from the simulations signified the importance of the temperature difference between the wall surface and the indoor air temperature. The temperature difference had a direct relationship with sensor accuracy and measurement representativeness, where smaller temperature difference was associated with higher accuracy.

scholarly journals Study on Flow and Heat Transfer Characteristics of Supercritical Kerosene in a Round Tube

2020 ◽  
Vol 316 ◽  
pp. 03003
Author(s):  
Feng Gao ◽  
Qian Zhang ◽  
Hongyu Xiao ◽  
Fengli Chen ◽  
Xuefeng Xia
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Inlet Temperature ◽  
Wall Surface ◽  
Heat Transfer Characteristics ◽  
Navier Stokes Equation ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Wall Surface Temperature ◽  
Central Flow

The finite volume discrete solution of the Navier-Stokes equation and the RNG model of the turbulence model are used to numerically simulate the flow and heat transfer characteristics of supercritical kerosene in a circular tube. The results show that as the inlet mass flow increases, the wall surface temperature and the central flow oil temperature gradually decrease, and the pressure loss becomes larger. As the inlet temperature increases, the wall surface temperature and the central flow oil temperature both increase. When the heat flux density is constant, as the pressure increases, the deterioration of heat transfer will be weakened, and increasing the pressure can improve the effect of convection heat transfer.

Simulation and Optimization of Homogeneous Decomposition of Sulfur Trioxide Gas on a Catalytic Surface

2005 ◽  
Author(s):  
Kiran K. Muramalla ◽  
Yitung Chen ◽  
Anthony E. Hechanova
Keyword(s):  
Heat Exchanger ◽  
Numerical Model ◽  
Surface Temperature ◽  
Flow Rate ◽  
Sulfur Trioxide ◽  
Tube Length ◽  
Two Dimensional ◽  
Wall Surface ◽  
Wall Surface Temperature ◽  
Homogeneous Decomposition

This paper deals with the development of a two-dimensional numerical model to predict the wall-catalyzed homogeneous decomposition of sulfur trioxide in a tubular component geometry for the production of hydrogen by the sulfur-iodine thermochemical water splitting cycle, a candidate cycle in the U.S. Department of Energy Nuclear Hydrogen Initiative. The reacting fluid is a mixture of sulfur trioxide gas and water vapor inside the tubes of a heat exchanger. The heat exchanger is made of Incoloy alloy 800H with ALFA-4 coated on the inner walls which acts as a catalyst. Decomposition of sulfur trioxide depends on many different parameters such as wall surface temperature, mole flow rate of the reacting mixture, diameter of the reactor tube, length of the reactor tube, operating pressure and inlet temperature of the reacting mixture. The effects of wall surface temperature, diameter of the reactor tube and mole flow rate on the decomposition of sulfur trioxide were investigated using a two-dimensional numerical model using Computational Fluid Dynamics (CFD) techniques. The preprocessor GAMBIT was used to create a computational mesh and the CFD software package FLUENT 6.2.16 [1] which is based on finite volume methods was used to simulate the problem. Both FLUENT 6.2.16 and Tecplot 10.0 are used to post process the problem.

scholarly journals Parameterization of Urban Sensible Heat Flux from Remotely Sensed Surface Temperature: Effects of Surface Structure

2019 ◽  
Vol 11 (11) ◽  
pp. 1347 ◽  
Author(s):  
Jinxin Yang ◽  
Massimo Menenti ◽  
E. Scott Krayenhoff ◽  
Zhifeng Wu ◽  
Qian Shi ◽  
...  
Keyword(s):  
Heat Flux ◽  
Surface Temperature ◽  
Sensible Heat Flux ◽  
Effective Resistance ◽  
Three Dimensions ◽  
Sensible Heat ◽  
Wall Surface ◽  
Surface Temperatures ◽  
Flux Parameterization ◽  
The Impact

Sensible heat exchange has important consequences for urban meteorology and related applications. Directional radiometric surface temperatures of urban canopies observed by remote sensing platforms have the potential to inform estimations of urban sensible heat flux. An imaging radiometer viewing the surface from nadir cannot capture the complete urban surface temperature, which is defined as the mean surface temperature over all urban facets in three dimensions, which includes building wall surface temperatures and requires an estimation of urban sensible heat flux. In this study, a numerical microclimate model, Temperatures of Urban Facets in 3-D (TUF-3D), was used to model sensible heat flux as well as radiometric and complete surface temperatures. Model data were applied to parameterize an effective resistance for the calculation of urban sensible heat flux from the radiometric (nadir view) surface temperature. The results showed that sensible heat flux was overestimated during daytime when the radiometric surface temperature was used without the effective resistance that accounts for the impact of wall surface temperature on heat flux. Parameterization of this additional resistance enabled reasonably accurate estimates of urban sensible heat flux from the radiometric surface temperature.

scholarly journals Cooling and Energy-Saving Performance of Different Green Wall Design: A Simulation Study of a Block

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2912 ◽  
Author(s):  
Jiayu Li ◽  
Bohong Zheng ◽  
Wenquan Shen ◽  
Yanfen Xiang ◽  
Xiao Chen ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Energy Saving ◽  
Air Temperature ◽  
Cooling Power ◽  
Wall Surface ◽  
Low Carbon ◽  
Outdoor Air ◽  
Green Wall ◽  
Green Walls ◽  
Wall Surface Temperature

To mitigate the urban heat island (UHI) and release the low carbon potential of green walls, we analyzed the cooling and energy-saving performance of different green wall designs. Envi-met was applied as the main simulation tool, and a pedestrian street named Yuhou Street was selected as the study object. Four designs of walls were summarized and simulated, demonstrating the living wall system (LWS). Super soil had superiority in cooling and energy saving. Outdoor air temperature, indoor air temperature, outside wall surface temperature, and inside wall surface temperature were analyzed. Apart from the outdoor air temperature, the other three temperatures were all significantly affected by the design of green walls. Finally, energy savings in building cavities were determined. The indoor energy saving ratio of the LWS based on super soil reached 19.92%, followed by the LWS based on boxes at 15.37%, and green facades wall at 6.29%. The indoor cooling powers on this typical day showed that the cooling power of the LWS based on super soil was 8267.32 W, followed by the LWS based on boxes at 6381.57 W, and green facades wall at 2610.08 W. The results revealed the difference in cooling and energy-saving performance of different green walls in this typical hot summer area.

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