N. Govindaraj, A. K. Singh, Pankaj Shukla

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-8, 2020, DOI:10.5098/hmt.15.20

Abstract A numerical study of fluid flow over stretching sheet with temperature dependent properties has been performed induced by mixed convection. The significant variation of the Prandtl number and viscosity in the temperature is observed [see table 1]. Viscosity and Prandtl number are vary in inverse of the linear function. The physical problem modeled in the mathematical equations in dimension form, which is converted to the non-dimensional equations by applying similarity transformations and suitable boundary conditions. The mathematical modelling problem is transformed PDE’s are numerically solved using Quasilinearization technique and FDM. The current numerical data has been presented in terms of… More >

Revathi Gadamsetty^a,*, Venkata Subrahmanyam Sajja^b , P. Sudam Sekhar^c, Dhaneshwar Prasad^d,†

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-7, 2020, DOI:10.5098/hmt.15.18

Abstract Hydrodynamic lubrication characteristics of asymmetric rollers lubricated by non-Newtonian incompressible Bingham plastic fluid are analyzed in this work. It narrates the qualitative research with the rigid system in which the viscosity of the particular non-Newtonian Bingham plastic substance is considered to become the function of hydrodynamic pressure. The equations considered in this work like equation of motion along with continuity and energy equations are solved numerically using MATLAB after particular analytical steps. Resulting from this particular work, it is identified that there is some notable change in temperatures, pressure, load and traction forces with Newtonian and also non-Newtonian fluids both.… More >

S. Ravi Teja^a , Chellapilla V. K. N. S. N. Moorthy^b,*, S. Jayakumar^c , Ayyagari Kiran Kumar^d , V. Srinivas^c,*

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-9, 2020, DOI:10.5098/hmt.15.7

Abstract This article is a summary of research involving the evaluation of the thermo-physical properties of Mono-ethylene - glycol-based solar thermic fluids oxidized multiwalled carbon nanotubes. Nanofluids were prepared with Mono-ethylene glycol and water as base fluids in 100:0, 90:10 and 80:20 ratios. These base fluids of three categories were dispersed with purified and oxidized multiwalled carbon nanotubes (MWCNTs) in the weight fractions of 0.125, 0.25 and 0.5 percentages. The variation in zeta potential is studied to examine the dispersion stability during 2 months. Thermal conductivity and dynamic viscosity were measured by hot disk method and Anton paar viscometer respectively. Significant… More >

Xi Wang¹, Shan Qing^1,*, Zhumei Luo^1,*, Yiqin Liu^1,2, Zichang Shi¹, Jiachen Li¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.9, pp. 2399-2416, 2023, DOI:10.32604/fdmp.2023.028024

Abstract Propylene glycol-based MWCNT (multi-walled carbon nanotubes) nanofluids were prepared in the framework of a two-step method and by using a suitable PVP (polyvinyl pyrrolidone) dispersant. The BBD (Box-Behnken design) model was exploited to analyze 17 sets of experiments and examine the sensitivity of the absorbance to three parameters, namely the concentration of MWCNT, the SN ratio (mass ratio of carbon nanotubes to surfactants) and the sonication time. The results have revealed that, while the SN ratio and concentration of MWCNT have a strong effect on the absorbance, the influence of the sonication time is less important. The statistical method of… More >

Revathi Gadamsetty^a,*,† , Venkata Subrahmanyam Sajja^b, P. Sudam Sekhar^c, Dhaneshwar Prasad^d

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-6, 2021, DOI:10.5098/hmt.16.7

Abstract An attempt has been made to investigate hydrodynamic lubrication characteristics of asymmetric roller bearings lubricated by thin fluid film under the operating behavior of line contact for a heavily loaded rigid system for normal squeezing motion with cavitation points. The lubricant follows non-Newtonian incompressible Bingham plastic fluid model where the fluid viscosity is supposed to vary with hydrodynamic pressure . The equations which govern the fluid flow such as continuity and momentum equation are solved first analytically and later numerically using MATLAB. The numerical results are achieved for the velocity, pressure, load, and traction forces by varying different physical parameters… More >

A. Sahaya Jenifer^a , P. Saikrishnan^a,*, J. Rajakumar^b

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-8, 2021, DOI:10.5098/hmt.17.4

Abstract This paper examines the steady magnetohydrodynamic (MHD) flow of water over a yawed cylinder with variable fluid properties and non-uniform mass transfer. The impact of viscous dissipation is taken into consideration. The velocity and temperature fields are governed by coupled nonlinear partial differential equations together with boundary constraints. These governing equations are converted to dimensionless form with suitable non-similar transformations and then solved using an implicit finite difference method and the quasi-linearization technique. The results indicate that the yaw angle enhancement declines the skin friction coefficient in the axial direction and the heat transfer coefficient. It is also ascertained that… More >

Yan-Juan Zhao^a,*, Yu-Liang Zhang^b,† , Chen-Liang Zhang^b

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-7, 2021, DOI:10.5098/hmt.17.3

Abstract Vortex flowmeter adopts advanced micro processing technology, which has the advantages of strong function, wide flow range, simple operation and maintenance, convenient installation and use. It is widely used in petroleum, chemical industry, electric power, metallurgy, urban gas supply and other industries to measure various gas flows. In order to study the characteristics of the inner flow passage of the vortex flowmeter and reach the normal working standard of the vortex flowmeter, this paper uses CFX to calculate the turbulent kinetic energy, eddy viscosity and flow velocity of the inner flow passage of the vortex flowmeter and analyze their distribution,… More >

Ramzy S. Hamied^1,*, Anwar N. Mohammed Ali¹, Khalid A. Sukkar²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.8, pp. 2027-2039, 2023, DOI:10.32604/fdmp.2023.027312

Abstract The process of transporting crude oil across pipelines is one of the most critical aspects of the midstream petroleum industry. In the present experimental work, the effect of temperature, pressure drop, and pipe diameter on the flow rate of heavy crude oil have been assessed. Moreover, the total discharge and energy losses have been evaluated in order to demonstrate the improvements potentially achievable by using solar heating method replacing pipe, and adjusting the value of the initial pressure difference. Crude oil of API = 20 has been used for the experiments, with the studied pipelines sections connecting the separator unit to… More > Graphic Abstract

Jiachen Li^1,2, Wenlong Deng³, Shan Qing^1,2,*, Yiqin Liu⁴, Hao Zhang^1,2, Min Zheng^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.8, pp. 2181-2200, 2023, DOI:10.32604/fdmp.2023.027299

Abstract In this study, comparing multiple models of machine learning, a multiple linear regression (MLP), multilayer feed-forward artificial neural network (BP) model, and a radial-basis feed-forward artificial neural network (RBF-BP) model are selected for the optimization of the thermal properties of TiO₂/water nanofluids. In particular, the least squares support vector machine (LS-SVM) method and radial basis support vector machine (RB-SVM) method are implemented. First, curve fitting is performed by means of multiple linear regression in order to obtain bivariate correlation functions for thermal conductivity and viscosity of the nanofluid. Then the aforementioned models are used for a predictive analysis of the… More >

Dadang Mohamad^1,*, Mohammed Abed Jawad², John William Grimaldo Guerrero³, Tonton Taufik Rachman⁴, Huynh Tan Hoi⁵, Albert Kh. Shaikhlislamov⁶, Mustafa M. Kadhim⁷, Saif Yaseen Hasan⁸, A. Surendar⁹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.3, pp. 851-866, 2022, DOI:10.32604/fdmp.2022.019485

Abstract

Further development in the field of geothermal energy require reliable reference data on the thermophysical properties of geothermal waters, namely, on the thermal conductivity and viscosity of aqueous salt solutions at temperatures of 293–473 K, pressures Ps = 100 MPa, and concentrations of 0–25 wt.%. Given the lack of data and models, especially for the dynamic viscosity of aqueous salt solutions at a pressure of above 40 MPa, generalized formulas are presented here, by which these gaps can be filled. The article presents a generalized formula for obtaining reliable data on the thermal conductivity of water aqueous solutions of salts… More >