A comparative analysis of engine characteristics from various biodiesels: Numerical study

2019 ◽  
Vol 180 ◽  
pp. 904-923 ◽  
Author(s):  
Upendra Rajak ◽  
Tikendra Nath Verma
Keyword(s):  
Comparative Analysis ◽  
Numerical Study

scholarly journals Numerical study of surface energy partitioning on the Tibetan Plateau: comparative analysis of two biosphere models

2009 ◽  
Vol 6 (6) ◽  
pp. 10849-10881
Author(s):  
J. Hong ◽  
J. Kim
Keyword(s):  
Comparative Analysis ◽  
Tibetan Plateau ◽  
Surface Energy ◽  
Summer Monsoon ◽  
Numerical Study ◽  
Asian Summer Monsoon ◽  
Energy Partitioning ◽  
In Situ Observation ◽  
Observation Data ◽  
The Tibetan Plateau

Abstract. The Tibetan Plateau is a critical region in the research of biosphere-atmosphere interactions on both regional and global scales due to its relation to Asian summer monsoon and El Niño. The unique environment on the Plateau provides valuable information for the evaluation of the models' surface energy partitioning associated with the summer monsoon. In this study, we investigated the surface energy partitioning on this important area through comparative analysis of two biosphere models constrained by the in-situ observation data. Indeed, the characteristics of the Plateau provide a unique opportunity to clarify the structural deficiencies of biosphere models as well as new insight into the surface energy partitioning on the Plateau. Our analysis showed that the observed inconsistency between the two biosphere models was mainly related to: 1) the parameterization for soil evaporation; 2) the way to deal with roughness lengths of momentum and scalars; and 3) the parameterization of subgrid velocity scale for aerodynamic conductance. Our study demonstrates that one should carefully interpret the modeling results on the Plateau especially during the pre-monsoon period.

scholarly journals Comparative analysis of different surfaces for integrated solar heating and radiative cooling: A numerical study

Energy ◽  
2018 ◽  
Vol 155 ◽  
pp. 360-369 ◽  
Author(s):  
Mingke Hu ◽  
Bin Zhao ◽  
Xianze Ao ◽  
Yuehong Su ◽  
Yunyun Wang ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Numerical Study ◽  
Solar Heating ◽  
Radiative Cooling

Dynamic Characteristic Analysis of Rotating Blade with Transverse Crack - Part II: A Comparison Study of Different Crack Models

2020 ◽  
pp. 1-32
Author(s):  
Laihao Yang ◽  
Zheshuai Yang ◽  
Zhu Mao ◽  
Shuming Wu ◽  
Xuefeng Chen ◽  
...  
Keyword(s):  
Nonlinear Dynamics ◽  
Comparative Analysis ◽  
Nonlinear Effect ◽  
Numerical Study ◽  
Crack Depth ◽  
Harmonic Component ◽  
Characteristic Analysis ◽  
Load Amplitude ◽  
Rotating Blade ◽  
Comparative Results

Abstract This study aims at the comparative analysis and improvement of different analytical crack models for rotating blade. Part II of this study focuses on the comparative analysis of dynamic characteristics based on modified models mentioned in Part I. A nonlinear damage indicator (NDI) and an equivalent energy indicator (EEI) are introduced to characterize the nonlinear effect of crack from different perspectives. EEI offers a physical mechanism explanation of crack closing behavior, which is invisible. Meanwhile, NDI offers an observable indicator to quantify the nonlinearity of crack. It is demonstrated through the numerical study that the variation of NDI and EEI varies the same with each other, which cross-verified the validity of NDI and EEI for quantifying the nonlinear effect of crack. Comparative investigations are performed to analyze the effects of load amplitude, crack depth, and crack location on the nonlinear dynamics of cracked blade, and both NDI and EEI are utilized to quantify the nonlinear effects of crack. The comparative results suggest that NDI of the second order super-harmonic component increase with the increasing crack depth and excitation load amplitude and decreases with the increasing crack locations, while the variation of EEI follows the variation of NDI. This phenomenon indicates that the crack which is deeper and closer to blade root under a larger load will be more dangerous. This study's comparative results may provide some guidance for choosing the analytical crack models when analyzing the nonlinear dynamics of rotating cracked-blade and blade health monitoring.

NUMERICAL STUDY OF NATURAL CONVECTION IN ENCLOSED VOLUME

2016 ◽  
Vol 6 (3) ◽  
pp. 146-150 ◽  
Author(s):  
Darya O. KORTYAEVA ◽  
Maxim N. NIKITIN
Keyword(s):  
Comparative Analysis ◽  
Natural Convection ◽  
Numerical Study ◽  
Central Section ◽  
Convective Mixing ◽  
Heated Air ◽  
Sst Turbulence Model ◽  
Upward Velocity ◽  
Stationary Formulation ◽  
Coupling Algorithm

A numerical study of natural convection was conducted with Code Saturne soft ware package. A numerical model based on combined k-ω SST turbulence model was developed. The results of simulation of natural convection in enclosed volume of air were obtained in two variants of boundary conditions specification: by heat flux and by heat transfer coefficient. The problem was solved in a non-stationary formulation using a pressure-velocity coupling algorithm PISO. This simulation model adequacy is evaluated. Experimental data on the temperature profile in the central section is used as a benchmark criteria. Assumptions about the destructive factors reducing the accuracy of the solution, are partly supported by the results of comparative analysis of the intensity of convective mixing. Assumptions partially confirmed by the results of comparative analysis of the intensity of convective mixing, performed on the basis of upward velocity profiles for the heated air.

scholarly journals Comparative analysis of experimental data of testing heavy concrete with simulation results

2021 ◽  
Vol 18 (1) ◽  
pp. 53-59
Author(s):  
S. V. Tsvetkov ◽  
Keyword(s):  
Experimental Data ◽  
Comparative Analysis ◽  
Uniaxial Compression ◽  
Axial Compression ◽  
Numerical Study ◽  
Biaxial Compression ◽  
Short Term ◽  
Simulation Results ◽  
Comparison Of The Results

The article presents the results of comparison of experimental data of testing heavy concrete with the simulation results. There were studied data on the strength of concrete under short-term uniaxial compression, biaxial compression, compression with tension, and triaxial proportional compression. The model uses the characteristics obtained from the results of testing concrete under axial compression. Comparison of the results of numerical study and the testing results has shown a satisfactory convergence.

COMPARATIVE ANALYSIS OF BONE STRAIN DISTRIBUTION IN HIP SURFACING – NUMERICAL STUDY

2012 ◽  
Vol 45 ◽  
pp. S288
Author(s):  
António Ramos ◽  
Carlos Relvas ◽  
António Completo ◽  
José A. Simões
Keyword(s):  
Comparative Analysis ◽  
Strain Distribution ◽  
Numerical Study ◽  
Bone Strain

scholarly journals Numerical study of surface energy partitioning on the Tibetan plateau: comparative analysis of two biosphere models

2010 ◽  
Vol 7 (2) ◽  
pp. 557-568 ◽  
Author(s):  
J. Hong ◽  
J. Kim
Keyword(s):  
Comparative Analysis ◽  
Tibetan Plateau ◽  
Surface Energy ◽  
Summer Monsoon ◽  
Numerical Study ◽  
Asian Summer Monsoon ◽  
Energy Partitioning ◽  
In Situ Observation ◽  
Observation Data ◽  
The Tibetan Plateau

Abstract. The Tibetan Plateau is a critical region in the research of biosphere-atmosphere interactions on both regional and global scales due to its relation to Asian summer monsoon and El Niño. The unique environment on the Plateau provides valuable information for the evaluation of the models' surface energy partitioning associated with the summer monsoon. In this study, we investigated the surface energy partitioning on this important area through comparative analysis of two biosphere models constrained by the in-situ observation data. Indeed, the characteristics of the Plateau provide a unique opportunity to clarify the structural deficiencies of biosphere models as well as new insight into the surface energy partitioning on the Plateau. Our analysis showed that the observed inconsistency between the two biosphere models was mainly related to: 1) the parameterization for soil evaporation; 2) the way to deal with roughness lengths of momentum and scalars; and 3) the parameterization of subgrid velocity scale for aerodynamic conductance. Our study demonstrates that one should carefully interpret the modeling results on the Plateau especially during the pre-monsoon period.

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