M. Arun, J. Akhil, K. Noufal, Robin Baby, Darshitha Babu, M. Jose Prakash^*

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-9, 2017, DOI:10.5098/hmt.8.23

Abstract The supercritical turbulent flow of cryogenic methane flowing in a rocket engine cooing channel is numerically analysed by imposing constant heat flux at the bottom surface of the channel. The calculation scheme is validated by comparing the results obtained with experimental results reported in literature. The heat transfer coefficient is influenced by the strong variation in thermophysical properties of methane at super critical pressure. An increasing trend in the average value of Nusselt number is observed with aspect ratio. The efficacy of both Modified Jackson and Hall and Bishop empirical correlations in predicting Nusselt number is tested for cryogenic methane… More >

Kaprawi Sahim^* , Dewi Puspitasari^†

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-6, 2017, DOI:10.5098/hmt.8.16

Abstract One row of heated elliptical cylinder with aspect ratio 0.6 and 0.8 are studied to know the forced heat transfer performance. The transversal distance between the cylinders are changed and the heat transfer is observed. Numerical observation of the study is done by using finite volume method to solve the momentum equations in two dimension domains. The pressure term instead of velocity is obtained by measurement in a subsonic wind tunnel and then it is injected into the momentum equation. The results of the hydrodynamic calculation are then injected into the energy equation which is solved by the over relaxation… More >

Ammar Abdulkadhim^a,*, Azher Mouhsen Abed^a , Khaled Al-Farhany^b

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-7, 2018, DOI:10.5098/hmt.11.12

Abstract The conjugate natural convection heat transfer in a partially heated porous enclosure had been studied numerically. The governing dimensionless equations are solved using finite element method. Classical Darcy model have been used and the considering dimensionless parameters are modified Rayleigh number (10 ≤ Ra ≤ 10³), finite wall thickness (0.02 ≤ D ≤ 0.5), thermal conductivity ratio (0.1 ≤ K_r ≤ 10), and the aspect ratio (0.5 ≤ A≤ 10). The results are presented in terms of streamlines, isotherms and local and average Nusselt number. The results indicate that heat transfer can be enhanced by increasing the modified Rayleigh number,… More >

M. Arun^a,*, M. Jose Prakash^b

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-10, 2018, DOI:10.5098/hmt.11.9

Abstract Prediction of heat transfer deterioration in rocket engine coolant channels with supercritical flow is essential while designing high pressure rocket engines. Three-dimensional conjugate heat transfer of cryogenic methane in rectangular engine cooling channels at supercritical pressures with asymmetric heating imposed on the bottom channel surface is numerically investigated, focusing on the effects of key parameters such as aspect ratio, heat flux and coolant pressure. Due to the similarity of the coolant channel with that of an actual rocket engine, the results obtained herein are beneficial for the design and optimization of rocket engine cooling systems. Heat flux is varied from… More >

Emad D. Aboud¹ , Qusay Rasheed Al-Amir², Hameed K. Hamzah², Ammar Abdulkadhim³, Mustafa M. Gabir³, Salwan Obaid Waheed Khafaji², Farooq H. Ali^2,*

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-17, 2021, DOI:10.5098/hmt.17.19

Abstract The natural convection of nanofluid flow, which occurs between a sinusoidal-corrugated enclosure and a concentric inner cylinder has been numerically investigated. The two horizontal walls of this enclosure are considered adiabatic and two vertical corrugated walls are held at a constant value of the cold temperature while the inner concentric cylinder is heated isothermally. Different cylinder geometries (i.e, circular, square, rhombus, and triangular) located inside the enclosure are examined to find the best shape for optimum heat transfer. The physical and geometrical parameters influencing heat transfer are Rayleigh number (Ra=10³ -10⁶), undulation numbers (N=0,1 and 2), aspect ratios (AR=5, 2.5… More >

Olanrewaju M. Oyewola^a,b,*, Samuel I. Afolabi^b , Olawale S. Ismail^b

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-8, 2021, DOI:10.5098/hmt.17.11

Abstract The problem of natural convection in rectangular cavities with different aspect ratios has been numerically analyzed in this study. Cavities considered have their right vertical walls heated and cooled at the opposite with constant temperatures, while horizontal walls are kept adiabatic. The objective of this study is to ascertain the significant effects of Rayleigh numbers (Ra), Nusselt numbers (Nu) and aspect ratios (AR) on flow and heat transfer in rectangular cavities. The equations of Navier-Stokes and energy are solved by applying Galerkin weighted residual Finite Element Method. Parametric calculations are performed for Rayleigh numbers (Ra) ranging from 104 to 108… More >

Nina Graupner^1,*, Thiprada Poonsawat², Koranat Narkpiban^3,4, Jörg Müssig¹

Journal of Renewable Materials, Vol.11, No.5, pp. 2279-2300, 2023, DOI:10.32604/jrm.2023.025529

Abstract Thailand has a huge variability of bast fiber plants, some of which have been little researched regarding their applicability in composites. Bast fiber(bundle)s from different species were investigated and incorporated into a polylactide (PLA) matrix by injection molding. Hemp and kenaf were used as well-studied fibers, while roselle, Fryxell and paper mulberry are less extensively characterized. Tensile strength, tensile modulus and interfacial shear strength (IFSS) of single fiber(bundle)s were highest for hemp, followed by kenaf, roselle, Fryxell and paper mulberry. Despite the lower tensile strength and IFSS of paper mulberry, the highest tensile strength was achieved for the paper mulberry/PLA… More > Graphic Abstract

Hongtao Guo, Changrong Zhang, Binbin Lv, Li Yu^*

CMES-Computer Modeling in Engineering & Sciences, Vol.132, No.3, pp. 991-1010, 2022, DOI:10.32604/cmes.2022.020638

Abstract The static aeroelastic effect of aircraft ailerons with high aspect ratio at transonic velocity is investigated in this paper by the CFD/CSD fluid-structure coupling numerical simulation. The influences of wing static aeroelasticity and the ‘scissor opening’ gap width between aileron control surface and the main wing surface on aileron efficiency are mainly explored. The main purpose of this paper is to provide technical support for the wind tunnel experimental model of aileron static aeroelasticity. The results indicate that the flight dynamic pressure has a great influence on the static aeroelastic effect of ailerons, and the greater the dynamic pressure, the… More >

Mourad Najjaoui^1,*, Thami Ait-Taleb¹, Abdelhalim Abdelbaki², Zaki Zrikem², Hassan Chaib¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.5, pp. 1339-1348, 2022, DOI:10.32604/fdmp.2022.021564

Abstract In this paper, some effort is provided to optimize the geometry of a concrete hollow brick (used in the construction of building roofs) in order to increase the related thermal resistance, thereby reducing energy consumption. The analysis is conducted for three different configurations of the hollow concrete bricks. Coupling of conduction, natural convection and thermal radiation phenomena is considered. Moreover, the flows are assumed to be laminar and two-dimensional for the whole range of parameters examined. The conservation equations are solved by a finite difference method based on the control volumes approach and the SIMPLE algorithm for velocity-pressure coupling. The… More >

Mohammad Zohurul Islam¹, Rabindra Nath Mondal², Suvash C. Saha^1,*

Energy Engineering, Vol.119, No.2, pp. 453-472, 2022, DOI:10.32604/ee.2022.018160

Abstract

A depth understanding of fluid flow past a curved duct having rectangular cross-section with different aspect ratios (l) are essential for various engineering applications such as in chemical, mechanical, bio-mechanical and bio-medical engineering. So highly ambitious researchers have given significant attention to study new characteristics of fluid flow in a curved duct. The flow characterization in the rectangular duct has been studied over a wide range of numerical and selective experimental studies. However, proper knowledge with the effects of Coriolis force for different aspect ratios is important for better understanding of the transitional behaviour and the subsequent heat generation, which… More >