scholarly journals InSAR analysis of surface deformation over permafrost to estimate active layer thickness based on one-dimensional heat transfer model of soils

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Zhiwei Li ◽  
Rong Zhao ◽  
Jun Hu ◽  
Lianxing Wen ◽  
Guangcai Feng ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Layer Thickness ◽  
Active Layer ◽  
Surface Deformation ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Active Layer Thickness ◽  
One Dimensional

Estimation of active layer thickness from modeling and InSAR deformation data at QTP

2020 ◽  
Author(s):  
Rongxing Li ◽  
Tong Hao ◽  
Ping Lu ◽  
Gang Qiao ◽  
Lemin Chen ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Large Scale ◽  
Surface Deformation ◽  
Remote Sensing Data ◽  
Field Measurements ◽  
Active Layer Thickness ◽  
Quality Of Data ◽  
Spatial Coverage ◽  
Sbas Insar

<p>In context of global warming, permafrost, as an important component of cryosphere in the Qinghai-Tibetan Plateau (QTP) that is located in middle and low latitudes with a high radiation intensity of high Asia mountains, is particularly sensitive to climate changes. The active layer thickness (ALT) in a permafrost area is an important index to indicate its stability. Traditional methods for measuring ALT in QTP mainly rely on ground-based field surveys and accordingly are extremely time- consuming and labor-intensive. The field works provide a good quality of data at a single site, however, such measurements are limited in spatial coverage and difficult for multi-temporal acquisitions. In addition, the harsh environment in QTP is not suitable for large-scale field measurements. In this study, the ALT of permafrost in QTP is estimated using modelling and remote sensing data. Particularly, the surface deformation on permafrost, as detected by the long-term InSAR technique, is considered as an input to the inversion model of ALT. The time-series deformation results over an experimental permafrost area were obtained by the SBAS-InSAR technique. Then, combined with the soil characteristics of soil moisture and soil thermal conductivity in the Stefan model, the melting thickness was estimated. Finally, the resulting ALT was tested and verified against a set of in-situ borehole measurements of depth-temperature.</p>

scholarly journals A one-dimensional modeling study on the effect of advanced insulation coatings on internal combustion engine efficiency

2020 ◽  
pp. 146808742092158
Author(s):  
Alberto Broatch ◽  
Pablo Olmeda ◽  
Xandra Margot ◽  
Josep Gomez-Soriano
Keyword(s):  
Heat Transfer ◽  
Combustion Engine ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Insulation Material ◽  
One Dimensional ◽  
Engine Efficiency ◽  
Dimensional Modeling ◽  
The One ◽  
The Impact

This article presents a study of the impact on engine efficiency of the heat loss reduction due to in-cylinder coating insulation. A numerical methodology based on one-dimensional heat transfer model is developed. Since there is no analytic solution for engines, the one-dimensional model was validated with the results of a simple “equivalent” problem, and then applied to different engine boundary conditions. Later on, the analysis of the effect of different coating properties on the heat transfer using the simplified one-dimensional heat transfer model is performed. After that, the model is coupled with a complete virtual engine that includes both thermodynamic and thermal modeling. Next, the thermal flows across the cylinder parts coated with the insulation material (piston and cylinder head) are predicted and the effect of the coating on engine indicated efficiency is analyzed in detail. The results show the gain limits, in terms of engine efficiency, that may be obtained with advanced coating solutions.

scholarly journals ACTIVE LAYER THICKNESS RETRIEVAL OVER THE QINGHAI-TIBET PLATEAU FROM 2000 TO 2020 BASED ON INSAR-MEASURED SUBSIDENCE AND MULTI-LAYER SOIL MOISTURE

2021 ◽  
Vol XLIII-B3-2021 ◽  
pp. 437-442
Author(s):  
T. Chang ◽  
J. Han ◽  
Z. Li ◽  
Y. Wen ◽  
T. Hao ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Layer Thickness ◽  
Active Layer ◽  
Surface Deformation ◽  
Tibet Plateau ◽  
Active Layer Thickness ◽  
Permafrost Region ◽  
Radar Images ◽  
Soil Moisture Data ◽  
Qinghai Tibet Plateau

Abstract. Active layer thickness (ALT) is an important index to reflect the stability of permafrost. The retrieval of ALT based on Interferometric Synthetic Aperture Radar (InSAR) technology has been investigated recently in permafrost research. However, most of such studies are carried out in a limited extend and relatively short temporal coverage. The combination of temporal-spatial multi-layer soil moisture data and multi-temporal InSAR is a promising approach for the large-scale characterization of ALT. In this study, we employed Small Baseline Subset Interferometry (SBAS-InSAR) technology to obtain the seasonal surface deformation from radar images of Envisat and Sentinel-1 in a permafrost region of Qinghai-Tibet Plateau (QTP). We attempt to verify and calibrate the temporal-spatial multi-layer soil moisture product in combination with the in-situ data. Based on the land subsidence data and the temporal-spatial multi-layer soil moisture data, we further improve method to retrieve the ALT information. This paper describes the progress so far and point out the future work.

Experimental Measurement of Glass to Mold Heat Transfer for Computational Modeling of Container Production

2004 ◽  
Author(s):  
Matthew R. Hyre ◽  
Brenton L. Underwood
Keyword(s):  
Heat Transfer ◽  
Heat Flow ◽  
Glass Container ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Glass Temperature ◽  
Contact Conductance ◽  
One Dimensional ◽  
Experimental Apparatus ◽  
Container Production

Recent advances in numerical simulation capabilities have made the modeling of glass container forming processes feasible. These forming models must include large free surface deformations, viscoelastic behavior, conjugate heat transfer, and complex contact phenomena between the glass and the forming molds. One of the most critical inputs to these models is the heat flux between the glass and mold. A simple one-dimensional heat transfer model was developed for use in conjunction with a complex three-dimensional forming model to determine the heat flow between the glass and forming mold. Initial comparisons to experimental results indicate the simple model captures the primary physics of heat flow during forming. This paper describes an experimental effort to determine the time varying contact conductance between molten glass and container forming molds. The experimental apparatus is capable of independently varying the glass pressure, glass temperature, mold temperature, and glass type. Initial validation of the experimentally determined contact conductance function in conjunction with the one-dimensional heat transfer model utilized within a glass forming model indicate good agreement between calculated and measured results. These forming models are now able to determine final glass container properties without having to resort to the trial-and-error process currently utilized in glass container production.

scholarly journals Numerical Simulation of One-Dimensional Fractional Nonsteady Heat Transfer Model Based on the Second Kind Chebyshev Wavelet

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Fuqiang Zhao ◽  
Jiaquan Xie ◽  
Qingxue Huang
Keyword(s):  
Heat Transfer ◽  
Fractional Order ◽  
Operational Matrix ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Nonsteady Heat ◽  
One Dimensional ◽  
Linear Algebraic Equations ◽  
Chebyshev Wavelet ◽  
Nonsteady Heat Transfer

In the current study, a numerical technique for solving one-dimensional fractional nonsteady heat transfer model is presented. We construct the second kind Chebyshev wavelet and then derive the operational matrix of fractional-order integration. The operational matrix of fractional-order integration is utilized to reduce the original problem to a system of linear algebraic equations, and then the numerical solutions obtained by our method are compared with those obtained by CAS wavelet method. Lastly, illustrated examples are included to demonstrate the validity and applicability of the technique.

Sign in / Sign up

Export Citation Format

Share Document