scholarly journals The influence of solar heating upon ground temperature

2021 ◽  
Vol 2116 (1) ◽  
pp. 012120
Author(s):  
A M Sousa ◽  
L Azevedo ◽  
M J Pereira ◽  
H A Matos
Keyword(s):  
Solar Radiation ◽  
Analytical Solution ◽  
Physical Properties ◽  
Solar Heating ◽  
Ground Temperature ◽  
Climatological Data ◽  
Intraday Data ◽  
Conservation Model ◽  
Transient Thermal ◽  
Volume Method

Abstract To predict the superficial ground temperature due to solar radiation as a function of the depth and rock physical properties, the Finite Volume Method was employed upon an energy conservation model. ANSYS Transient Thermal was selected to simulate a 3D geological volume, 1625 m wide, 2000 m long and with variable height as a function of topographical data. As a result, the variability of ground temperature during a 24h day was assessed. A set of climatological data was used to evaluate the ground temperature for the colder periods. The numerical results were compared against the Kusuda and Achenbach’s analytical solution to evaluate the possibility of extending the validity of a widely used method, from daily to intraday data.

scholarly journals Evaluation and Recommendations for Improving the Accuracy of an Inexpensive Water Temperature Logger

2013 ◽  
Vol 30 (7) ◽  
pp. 1576-1582 ◽  
Author(s):  
S. J. Lentz ◽  
J. H. Churchill ◽  
C. Marquette ◽  
J. Smith
Keyword(s):  
Surface Layer ◽  
Solar Radiation ◽  
Water Temperature ◽  
Solar Heating ◽  
Bias Error ◽  
Mean Square ◽  
Temperature Logger ◽  
Accurate Temperature ◽  
Rms Error ◽  
Rms Errors

Abstract Onset's HOBO U22 Water Temp Pros are small, reliable, relatively inexpensive, self-contained temperature loggers that are widely used in studies of oceans, lakes, and streams. An in-house temperature bath calibration of 158 Temp Pros indicated root-mean-square (RMS) errors ranging from 0.01° to 0.14°C, with one value of 0.23°C, consistent with the factory specifications. Application of a quadratic calibration correction substantially reduced the RMS error to less than 0.009°C in all cases. The primary correction was a bias error typically between −0.1° and 0.15°C. Comparison of water temperature measurements from Temp Pros and more accurate temperature loggers during two oceanographic studies indicates that calibrated Temp Pros have an RMS error of ~0.02°C throughout the water column at night and beneath the surface layer influenced by penetrating solar radiation during the day. Larger RMS errors (up to 0.08°C) are observed near the surface during the day due to solar heating of the black Temp Pro housing. Errors due to solar heating are significantly reduced by wrapping the housing with white electrical tape.

scholarly journals Predictive Performance of Hargreaves Model in Estimating Solar Radiation in Yola, Adamawa State Nigeria Using Minimum Climatological Data

2018 ◽  
pp. 1-8
Author(s):  
Ojo Samuel ◽  
Alimi Taofeek Ayodele ◽  
Amos Anna Solomon
Keyword(s):  
Solar Radiation ◽  
Model Performance ◽  
Predictive Performance ◽  
Global Solar Radiation ◽  
Climatic Data ◽  
Climatological Data ◽  
University Of Technology ◽  
Hargreaves Model ◽  
The Many

Mathematical models have been very useful in reducing challenges encountered by researchers due to the inability of having solar radiation data or lack of instrumental sites at every point on the Earth.  This work aimed at investigating the prediction performance of Hargreaves-Samani’s model in estimating global solar radiation (GSR) out of the many other empirical models so far formulated for this purpose. This model basically uses maximum and minimum temperature data and basically used in mid-latitudes. The paper attempts to assess the predictive performance of Hargreaves-Samani’s model in the Savanna region using Yola as a case study. Estimated values of GSR from one month data adopted from the Meteorological station of the Department of Geography, Federal University of Technology, Yola, Nigeria was used for this purpose. Using this model shows a 95% index of agreement (IA) with the observed values; which suggests a good model performance and can also be used in estimating global solar radiation in the Savanna region particularly in areas with little or no such climatic data.

scholarly journals Transient Thermal Effects in Sedimentary Basins with Normal Faults and Magmatic Sill Intrusions—A Sensitivity Study

Geosciences ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 160 ◽  
Author(s):  
Magnhild Sydnes ◽  
Willy Fjeldskaar ◽  
Ivar Grunnaleite ◽  
Ingrid Fjeldskaar Løtveit ◽  
Rolf Mjelde
Keyword(s):  
Physical Properties ◽  
Thermal Effects ◽  
Sedimentary Basins ◽  
Sensitivity Study ◽  
Fault Slip ◽  
Structural Development ◽  
Potential Source Rock ◽  
Magmatic Intrusions ◽  
Transient Thermal ◽  
Magmatic Sill

Magmatic intrusions affect the basin temperature in their vicinity. Faulting and physical properties of the basin may influence the magnitudes of their thermal effects and the potential source rock maturation. We present results from a sensitivity study of the most important factors affecting the thermal history in structurally complex sedimentary basins with magmatic sill intrusions. These factors are related to faulting, physical properties, and restoration methods: (1) fault displacement, (2) time span of faulting and deposition, (3) fault angle, (4) thermal conductivity and specific heat capacity, (5) basal heat flow and (6) restoration method. All modeling is performed on the same constructed clastic sedimentary profile containing one normal listric fault with one faulting event. Sills are modeled to intrude into either side of the fault zone with a temperature of 1000 °C. The results show that transient thermal effects may last up to several million years after fault slip. Thermal differences up to 40 °C could occur for sills intruding at time of fault slip, to sills intruding 10 million years later. We have shown that omitting the transient thermal effects of structural development in basins with magmatic intrusions may lead to over- or underestimation of the thermal effects of magmatic intrusions and ultimately the estimated maturation.

scholarly journals Analysis of the potential use of Trombe walls in Brazil: design recommendations

2020 ◽  
Vol 5 ◽  
pp. 4
Author(s):  
Fernando Antonio de Melo Sá Cavalcanti ◽  
Rosana Maria Caram
Keyword(s):  
Solar Radiation ◽  
Computer Simulations ◽  
Thermal Performance ◽  
Natural Ventilation ◽  
Solar Heating ◽  
Heating And Cooling ◽  
Heated Air ◽  
Trombe Wall ◽  
Potential Use ◽  
Passive Strategy

In this paper, the thermal performance of a standard environment was evaluated based on the use of a Trombe wall with different configurations and types of use, as the potential for using this passive strategy is still little studied in Brazil. This device is capable of absorbing energy from solar radiation by heating the air in this greenhouse and this heated air can be directed to the interior or exterior of the building depending on the purpose. This air can be used to heat the room or cool it by means of natural ventilation. The analysis of this research was based on a series of computer simulations using the EnergyPlus software, version 7.0 in order to quantify and classify the thermal performance of a standard environment equipped with this component, under the various construction configurations. Both for heating and cooling environments. The use of Trombe walls improved the thermal comfort of users in buildings located in Brazil, depending on the climate where they are located, promoting natural ventilation and passive solar heating, allowing the potential of this device to be investigated in the most diverse Brazilian regions.

Experience on Transient Thermal Modeling of Sodium to Sodium Heat Exchanger Using FDM and FVM

2010 ◽  
Author(s):  
Sourabh Agarwal ◽  
K. Revathy ◽  
I. Banerjee ◽  
G. Padma Kumar ◽  
C. A. Babu ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Finite Difference Method ◽  
Heat Balance ◽  
Operating Conditions ◽  
Outlet Temperature ◽  
Intermediate Heat Exchanger ◽  
Modelling Techniques ◽  
The Finite Difference Method ◽  
Transient Thermal ◽  
Volume Method

Several intermediate heat exchanger (IHX) modelling techniques were examined, in order to predict the outlet temperature of primary and secondary sodium at different operating conditions. In the present study, two different approaches namely the Finite Difference Method (FDM) with nodal heat balance and modified nodal heat balance schemes; and Finite Volume Method (FVM) using simple upwind, exponential extrapolation and QUICK schemes have been attempted.

scholarly journals Shortwave Spectral Radiative Signatures and Their Physical Controls

2019 ◽  
Vol 32 (15) ◽  
pp. 4805-4828 ◽  
Author(s):  
Jake J. Gristey ◽  
J. Christine Chiu ◽  
Robert J. Gurney ◽  
Keith P. Shine ◽  
Stephan Havemann ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Physical Properties ◽  
Spectral Reflectance ◽  
Spatial Scales ◽  
Monsoon Season ◽  
Spectral Characteristics ◽  
Great Promise ◽  
Earth System ◽  
Spectral Signatures ◽  
Cloud Regimes

AbstractThe spectrum of reflected solar radiation emerging at the top of the atmosphere is rich with Earth system information. To identify spectral signatures in the reflected solar radiation and directly relate them to the underlying physical properties controlling their structure, over 90 000 solar reflectance spectra are computed over West Africa in 2010 using a fast radiation code employing the spectral characteristics of the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY). Cluster analysis applied to the computed spectra reveals spectral signatures related to distinct surface properties, and cloud regimes distinguished by their spectral shortwave cloud radiative effect (SWCRE). The cloud regimes exhibit a diverse variety of mean broadband SWCREs, and offer an alternative approach to define cloud type for SWCRE applications that does not require any prior assumptions. The direct link between spectral signatures and distinct physical properties extracted from clustering remains robust between spatial scales of 1, 20, and 240 km, and presents an excellent opportunity to understand the underlying properties controlling real spectral reflectance observations. Observed SCIAMACHY spectra are assigned to the calculated spectral clusters, showing that cloud regimes are most frequent during the active West African monsoon season of June–October in 2010, and all cloud regimes have a higher frequency of occurrence during the active monsoon season of 2003 compared with the inactive monsoon season of 2004. Overall, the distinct underlying physical properties controlling spectral signatures show great promise for monitoring evolution of the Earth system directly from solar spectral reflectance observations.

Material Properties of Refractory Concrete under High Temperature

2015 ◽  
Vol 1126 ◽  
pp. 155-160
Author(s):  
Stanislav Šťastník ◽  
František Šot ◽  
Jiří Vala
Keyword(s):  
High Temperature ◽  
Solar Radiation ◽  
Physical Properties ◽  
Material Properties ◽  
Refractory Concrete ◽  
Thermal Storage ◽  
Thermal Transfer ◽  
The Core

The paper presents the validation of physical properties of refractory concrete with heavy filling, using the measurements under high temperature, assumed for the construction of a thermal storage. The whole system, consisting of the storage core and of the insulation container, is characterized by non-stationary thermal transfer, supplied from solar radiation into the core. The validation of behaviour of the system (including its sleeping state and the dynamics of charging and discharging) is needed for the optimization of its size parameters.

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