Pankaj Saha^a, Gautam Biswas^a,b,*

Frontiers in Heat and Mass Transfer, Vol.2, No.3, pp. 1-5, 2011, DOI:10.5098/hmt.v2.3.3008

Abstract Detailed flow structure in turbulent flows through a rectangular channel containing built-in winglet type vortex generators have been analyzed by means of solutions of the full Navier-Stokes equations using a Large-Eddy Simulation (LES) technique. The Reynolds number of investigation is 6000. The geometry of interest consists of a rectangular channel with a built-in winglet pair on the bottom wall with common-flow-down arrangement. The winglet pair induces streamwise longitudinal vortices behind it. The vortices swirl the flow around the axis parallel to the mainstream direction and disrupt the growth of thermal boundary layer entailing enhancement of heat transfer. The influence of… More >

Arafat A. Bhuiyan^a,1, A. K. M. Sadrul Islam^a, M. Ruhul Amin^b

Frontiers in Heat and Mass Transfer, Vol.3, No.3, pp. 1-9, 2012, DOI:10.5098/hmt.v3.3.3006

Abstract This numerical analysis presents the airside performance of a wavy fin-and-tube heat exchanger having 4 row configurations considering steady, incompressible and 3D flow using Commercial CFD Code ANSYS CFX 12.0. Results are presented in the form of friction factor (f), Colburn factor (j) and efficiency index (j/f). The numerical procedure has been validated by comparison with published numerical and experimental results and good agreement has been observed. A series of numerical calculations have been carried out in order to analyze the influence of various geometric characteristics on different fields as well as on the heat transfer and pressure drop and… More >

Wei Wang¹, Yang Yu¹, Simin Luo^2,*, Wenlin Liu², Wei Tang¹, Yuanbo Ye¹

Energy Engineering, Vol.121, No.2, pp. 315-337, 2024, DOI:10.32604/ee.2023.042082

Abstract As an effective approach to achieve the “dual-carbon” goal, the grid-connected capacity of renewable energy increases constantly. Photovoltaics are the most widely used renewable energy sources and have been applied on various occasions. However, the inherent randomness, intermittency, and weak support of grid-connected equipment not only cause changes in the original flow characteristics of the grid but also result in complex fault characteristics. Traditional overcurrent and differential protection methods cannot respond accurately due to the effects of unknown renewable energy sources. Therefore, a longitudinal protection method based on virtual measurement of current restraint is proposed in this paper. The positive… More >

Husam Rashid Hudear^*, Saad Najeeb Shehab

Frontiers in Heat and Mass Transfer, Vol.21, pp. 367-383, 2023, DOI:10.32604/fhmt.2023.042639

Abstract This paper presents a numerical emulation study of heat transmission through tube banks in three-dimensions. Staggered configuration is displayed by fluid dynamics using computer programs (CFD) software (ANSYS fluent). The computer model is used to predict the values of the Nusselt number when changing the values of heat flux and longitudinal pitch. The longitudinal pitch (SL/D) of 1.3, 1.8, and 2.4 mm. The transverse pitch (ST/D) of 1.5 mm, and also considered Reynolds numbers 10000, 13000, 17000, and 190000. The staggered configuration of the tube bundle is demonstrated to investigate the impact of this arrangement on the heat transmission rate… More >

Lu He^1,*, Yuhang Zhou¹, Guoqing Zhu¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.08939

Abstract The longitudinal position of the fire source is one of the key parameters affecting the flow field characteristics in a long-distance tunnel. In this paper, a series of numerical simulations were carried out to analyze the influence of the longitudinal position and the heat release rate (HRR) on the induced airflow on both sides of the fire source and the smoke movement behaviors characteristics in the long-distance tunnel. It is found that under the induction of thermal pressure, an asymmetric induced air flow is formed near the fire source, resulting in asymmetric dynamic parameters of ceiling jet. The wind speed… More >

Changyao Chen¹, Jialei Song^1,*, Ling Yin¹, Yizhe Li², Zheng Yuan², Yuhan Li³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.09859

Abstract Bird can switch between high maneuverability and high stability due to its ability to substantially morph wings and tail. Tail as an auxiliary lift surface, plays an important role on lift and drag production and also significantly affects the longitudinal stability. In this study, we reconstruct a high-fidelity barn owl model using the point cloud of its surface obtained from high-speed photogrammetry, and simulate the fluid dynamics using a commercial software. By virtually manipulating the tail to a series of postures, we analyze the aerodynamics and static stability for each tail posture, investigating the strategy to adjust the stability during… More >

S. Duroudier¹ , S. Chardonnel¹, B. Mericskay² , I. Andre-Poyaud¹ , O. Bedel³ , S. Depeau², T. Devogele⁴, L. Etienne⁴, A. Lepetit², C. Moreau⁴, N. Pelletier² , E. Ployon¹, K. Tabaka¹

Revue Internationale de Géomatique, Vol.30, No.1, pp. 127-148, 2020, DOI:10.3166/rig.2020.00105

Abstract This paper aims at proposing a data quality diagnosis and cleansing data methodology experimented on an individual mobility survey (Mobi’Kids program). The first section presents the theoretical approach to highlight the issue of a data quality diagnosis applied to heterogeneous data collected from mixed methods (GPS tracks, surveys, observations). Secondly, two typologies of major errors are discussed according to their origin (GPS, algorithm, survey) and their nature (completeness, accuracy, consistency). A processing chain is thirdly defined to improve both internal and external data quality in order to the perspective of a replicable methodology.

RÉSUMÉ
Cet article a pour objectif de… More >

Rajen Kumar Nayak^a,* , Ravi Shankar Prasad^a,† , Ujjwal Kumar Nayak^a, Amit Kumar Gupta^b

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-12, 2022, DOI:10.5098/hmt.19.22

Abstract The present experimental work has been carried out for a solar air heater under cross flow condition having inline hole jet plate between bottom plate and absorber plate with longitudinal fins underside the absorber surface. The performance of this inline hole jet plate solar air heater is compared with the performance of jet plate solar air heaters without longitudinal fins under cross and non-cross flow conditions for similar geometrical and operational parameters. Results are presented for mass flow rates of air, ṁ₁ = 0.020 - 0.070 kg/sec, ṁ₂ = 0.018 - 0.041 kg/sec, flow Reynolds number, Re_ja2 = 2000 -… More >

Rajen Kumar Nayak^a,* , Ravi Shankar Prasad^a,† , Ujjwal Kumar Nayak^a, Amit Kumar Gupta^b

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-12, 2022, DOI:10.5098/hmt.19.7

Abstract This analytical study has been carried out on inline and staggered hole jet plate solar air heater with longitudinal fins attached underside the absorber surface under the cross flow and non-cross flow conditions of air through the channels for varying mass flow rate of air, ṁ₁ (50-300 kg/hm² ), jet hole diameter, D (6 mm-10 mm) and distance between the absorber and jet plate, Z₂ (5 cm-10 cm) with fixed number of jet holes, N (480 and 1008 for inline and staggered hole respectively) and pitch of the fins, p (3 mm). The result shows the performance of staggered hole… More >

Jeong Min Yang^1,2, Hyeon Ji Lee¹, Jae Hyun Kim^1,2,3,*

International Journal of Mental Health Promotion, Vol.25, No.4, pp. 579-594, 2023, DOI:10.32604/ijmhp.2022.027498

Abstract Objectives: This study was to longitudinally investigate the association between occupational change trajectories and mental health in the Korean population aged 45 years and older from the Korean Longitudinal Study of Aging (KLoSA). Methods: After excluding missing values, the data of 6,224 participants from the first to eighth waves of the KLoSA were analyzed using t-test, Analysis of variance (ANOVA), Group-based Trajectory Model (GBTM) from 1–5^th KLoSA and Time-Lagged Generalized estimating equation (GEE) model from 5–8^th KLoSA to analyze the association between occupational change trajectories and mental health in the Korean population aged 45 years and older. Results: An analysis… More >