K. Jyothi¹, Abhishek Dasore^2,3,*, R. Ganapati⁴, Sk. Mohammad Shareef⁵, Ali J. Chamkha⁶, V. Raghavendra Prasad⁷

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 79-105, 2024, DOI:10.32604/fhmt.2024.046891

Abstract In the current research, a thorough examination unfolds concerning the attributes of magnetohydrodynamic (MHD) boundary layer flow and heat transfer inherent to nanoliquids derived from Sisko Al₂O₃-Eg and TiO₂-Eg compositions. Such nanoliquids are subjected to an extending surface. Consideration is duly given to slip boundary conditions, as well as the effects stemming from variable viscosity and variable thermal conductivity. The analytical approach applied involves the application of suitable similarity transformations. These conversions serve to transform the initial set of complex nonlinear partial differential equations into a more manageable assembly of ordinary differential equations. Through the utilization of the FEM, these… More > Graphic Abstract

Mustafa Abdullah^*

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 141-156, 2024, DOI:10.32604/fhmt.2024.046788

Abstract This study investigates the influence of periodic heat flux and viscous dissipation on magnetohydrodynamic (MHD) flow through a vertical channel with heat generation. A theoretical approach is employed. The channel is exposed to a perpendicular magnetic field, while one side experiences a periodic heat flow, and the other side undergoes a periodic temperature variation. Numerical solutions for the governing partial differential equations are obtained using a finite difference approach, complemented by an eigenfunction expansion method for analytical solutions. Visualizations and discussions illustrate how different variables affect the flow velocity and temperature fields. This offers comprehensive insights into MHD flow behavior… More >

Fayi Yan^*, Xuejian Pei, He Lu, Shuzhen Zong

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 287-304, 2024, DOI:10.32604/fhmt.2023.045038

Abstract As compact and efficient heat exchange equipment, helically coiled tube-in-tube heat exchangers (HCTT heat exchangers) are widely used in many industrial processes. However, the thermal-hydraulic research of liquefied natural gas (LNG) as the working fluid in HCTT heat exchangers is rarely reported. In this paper, the characteristics of HCTT heat exchangers, in which LNG flows in the inner tube and ethylene glycol-water solution flows in the outer tube, are studied by numerical simulations. The influences of heat transfer characteristics and pressure drops of the HCTT heat transfers are studied by changing the initial flow velocity, the helical middle diameter, and… More >

Muhammad Abaid Ur Rehman^1,*, Muhammad Asif Farooq¹, Ahmed M. Hassan²

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 263-286, 2024, DOI:10.32604/fhmt.2023.044587

Abstract This paper proposes a mathematical modeling approach to examine the two-dimensional flow stagnates at over a heated stretchable sheet in a porous medium influenced by nonlinear thermal radiation, variable viscosity, and MHD. This study’s main purpose is to examine how thermal radiation and varying viscosity affect fluid flow motion. Additionally, we consider the convective boundary conditions and incorporate the gyrotactic microorganisms equation, which describes microorganism behavior in response to fluid flow. The partial differential equations (PDEs) that represent the conservation equations for mass, momentum, energy, and microorganisms are then converted into a system of coupled ordinary differential equations (ODEs) through… More >

Dewi Puspitasari¹, Diah Kusuma Pratiwi¹, Pramadhony Amran², Kaprawi Sahim^1,*

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 305-315, 2024, DOI:10.32604/fhmt.2023.041882

Abstract The natural convection from a vertical hot plate with radiation and constant flux is studied numerically to know the velocity and temperature distribution characteristics over a vertical hot plate. The governing equations of the natural convection in two-dimension are solved with the implicit finite difference method, whereas the discretized equations are solved with the iterative relaxation method. The results show that the velocity and the temperature increase along the vertical wall. The influence of the radiation parameter in the boundary layer is significant in increasing the velocity and temperature profiles. The velocity profiles increase with the increase of the radiation… More >

Calvin Hong Li^a, G. P. Peterson^b,*

Frontiers in Heat and Mass Transfer, Vol.1, No.2, pp. 1-10, 2010, DOI:10.5098/hmt.v1.2.3007

Abstract An experimental investigation of the Critical Heat Flux (CHF) and heat transfer coefficient (HTC) of two-phase heat transfer of de-Ionized (DI) water, pool boiling was conducted using several kinds of sintered copper microparticle porous uniform and modulated structures. The modulated porous structure reached a heat flux of 450 W/cm² and a heat transfer coefficient of 230,000 W/m2K. The thick and thin uniform porous structures achieved CHFs of 290 W/cm² and 227 W/cm² , respectively, and heat transfer coefficients of 118,000 W/m²K and 104,000 W/m²K. The mechanisms for the dramatically improved CHFs and HTCs were identified with assistance of a visualization… More >

Peter Kasten^a, Severin Zimmermann^a, Manish K. Tiwari^a, Bruno Michel^b, Dimos Poulikakos^a,*

Frontiers in Heat and Mass Transfer, Vol.1, No.2, pp. 1-10, 2010, DOI:10.5098/hmt.v1.2.3006

Abstract Electronic data center cooling using hot water is proposed for high system exergetic utility. The proof-of-principle is provided by numerically modeling a manifold micro-channel heat sink for cooling microprocessors of a data center. An easily achievable 0.5l/min per chip water flow, with 60°C inlet water temperature, is found sufficient to address the typical data center thermal loads. A maximum temperature difference of ~8°C was found between the solid and liquid, confirming small exergetic destruction due to heat transport across a temperature differential. The high water outlet temperature from the heat sink opens the possibility of waste heat recovery applications. More >

Dye-Zone A. Chen, Gang Chen^*

Frontiers in Heat and Mass Transfer, Vol.1, No.2, pp. 1-6, 2010, DOI:10.5098/hmt.v1.2.3005

Abstract We present a calculation of the thermally generated electromagnetic flux propagating along the in-plane direction of a polar, thin film. The approach is based on fluctuational electrodynamics and the fluctuation-dissipation theorem. We find that for silicon carbide films between 5 nm and 100 nm thick, the thinner films transport more in-plane flux due to the long propagation length of the anti-symmetric surface phonon-polariton mode. Comparison of results obtained from the fluctuation-dissipation approach and the kinetic theory approach shows favorable agreement. More >

Khalil Khanafer^a, Kambiz Vafai^b,*

Frontiers in Heat and Mass Transfer, Vol.1, No.2, pp. 1-9, 2010, DOI:10.5098/hmt.v1.2.3004

Abstract A study was conducted to demonstrate the applications of microcantilevers in biomedical and thermo/fluid fields. The deflection of the microcantilevers due to biomaterial and turbulence effects was highlighted in this work. The novel patented microcantilever assemblies that were presented in this study can increase the signal and decrease the unfavorable deflection due to flow disturbances. This work paves the road for researchers in the area microcantilever based biosensors to design efficient microsensor systems that exhibit minimal errors in the measurements. Fluid-structure interaction was also utilized to investigate some aspects of the fluid flow and heat transfer characteristics. More >

Kenneth M. Armijo, Van P. Carey^*

Frontiers in Heat and Mass Transfer, Vol.1, No.2, pp. 1-6, 2010, DOI:10.5098/hmt.v1.2.3003

Abstract This paper investigates the impact of Marangoni phenomena for low concentrations of 2-propanol/water and methanol/water mixtures. In real systems the addition of small levels of surface-active contaminants can affect the surface tension of the liquid-vapor interface and thermodynamic conditions in this region. Analysis was performed for three widely accepted binary mixture correlations to predict heat flux and superheat values for subatmospheric experimental data using bulk fluid and film thermodynamic properties. Due to the non-ideal nature of these alcohol/water mixtures, this study also employs an average pseudo single-component (PSC) coefficient in place of an ideal heat transfer coefficient (HTC) to improve… More >