Dual Solutions for Viscous Mixed Convection Flows in a Vertical Circular Duct: A Numerical Benchmark
S. Lazzari1, A. Barletta1 , E. Magyari1,2, and F. Piccinini3
1Dipartimento di Ingegneria Energetica, Nucleare e del Controllo Ambientale (DIENCA), University of Bologna, Bologna, Italy
2Institute of Building Technology, ETH - Zürich, Zürich, Switzerland
3Biomedical Engineering, Engineering School of Cesena, Cesena, Italy
Forced and free convection flow in a vertical isothermal circular duct is studied by taking into account the internal heating due to viscous dissipation. The momentum and energy balance equations lead to a nonlinear boundary value problem that is solved numerically by means of the finite-element software COMSOL Multiphysics.For any prescribed value of the average velocity smaller than a maximum, ...
P. Lamy-Bracq, J. Leroy, and C. Coulouarn
NEXTER Munitions, Bourges, France
ENSI Bourges, Bourges, France
The rheological behaviour of a biphasic material is quite difficult to model because of the difficulties to represent the evolution of the space position of each solid particle in the solid matrix. The first part of this study consider an equivalent material by homogeneisation method. The main point of this first part was the representation of the rotation of the rheological mobile. The second ...
M. Heidari, and P. Barrade
The core of this modelling is to study heat transfer and fluid dynamics processes for a compression expansion system, and the main particularity is that heat transfer and air movement are due to the movement of the piston. We have implemented a \"moving mesh\" solver to compute the volume changes of the compression chamber followed by a \"Fluid dynamics\" type solver. It allows correct ...
U. Shukla, and D. Gupta
 Department of Materials and Metallurgical Engineering, Indian Institute of Technology Kanpur, Uttar Pradesh, India
One of the major challenges faced by the semiconductor industry is that electronic circuits produce a lot of heat energy during their operation. And with the current scenario where the gates are packed so much close together, then the problem of heat generation has become extremely significant. So we are working towards the efficient heat management and dissipation solution for the heat generated ...
A-G. Ghiaus, M-A. Istrate, and A-M. Georgescu
Technical University of Civil Egineering, Bucharest, Romania
Analysis and optimization of air flow distribution inside drying kiln systems contribute to the improvement of the final product quality. The present study reports on the threedimensional numerical solution of air flow within a drying kiln enclosure. The air flow field is examined in different configurations and operation conditions. Depending on the off/on switched fans, we obtain various air ...
C. Wolluschek, F. Etcheverry, M. Cachile, and J. Gomba
Mecánica de Fluidos e Ingeniería Térmica, Centro tecnológico Cemitec, Noáin, Navarra, Spain
Grupo de Medios Porosos, Facultad de Ingeniería, UBA, Buenos Aires, Argentina
Instituto de Física Arroyo Seco, UNCPBA, Tandil, Argentina.
In this work, a COMSOL model that predicts velocity and concentration fields inside an X-shaped millichannel (4 mm diameter) is developed. Water and a ink low concentration are injected simultaneously in the two inlets of the device. The mass transfer problem is solved by a Fickian model (solute concentration is low compared with the solvent). The parameters in this study are: initial inlet mass ...
A.-G. Ghiaus, M.-A. Istrate, A. Georgescu
Technical University of Civil Engineering, Bucharest, Romania
The paper presents the analysis and optimization of the ventilation system inside of a drying lumber kiln. As with any part of the manufacturing process, improper drying techniques cause quality degradation and considerable amount of energy loose. The improvement and optimization of air distribution systems in drying kilns contributes to the preservation of the wood quality. The performance of ...
S. Agarwal, C. A. Babu, P. Kalyanasundaram, and G. Vaidyanathan
Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam
Intermediate heat exchanger (IHX) in a pool-type liquid metal cooled fast breeder reactor is an important heat exchanging component as it transfer heat from the radioactive primary sodium in the pool to the non-radioactive secondary sodium. The secondary sodium ultimately heats up water in a steam Generator (SG) to produce the steam for power generation. Intermediate heat exchanger is a ...
N. Jand, A. Scarpetta, and M. Stefano
Chemical Engineering Department, University of L’Aquila, L’Aquila, Italy
Faculty of Engineering, University of L'Aquila, L’Aquila, Italy
The modeling of sublimation form a rotating cylinder of solid naphthalene in a confined vessel has been performed by coupling the model of incompressible Newtonian fluid flow with the model of the dilute solutions. Preliminary a 2D axisymmetric system with swirl flow function for laminar and turbulent regimes has been considered. In the turbulent regime the RANS model with default parameter is ...
COMSOL Derived Universal Scaling Model For Low Reynolds Number Viscous Flow Through Microfabricated Pillars – Applications to Heat Pipe Technology
N. Srivastava, and C.D. Meinhart
Department of Mechanical Engineering, University of California Santa Barbara, Santa Barbara California, USA
Cooling of high-power density electronic devices remains a challenge. Microfluidic heat-pipes with the potential of achieving ultra-high thermal conductivities offer a low-cost technology for cooling electronics. To achieve high thermal conductivity, it is critical to maximize the rate of liquid transport inside the heat pipe. We propose a novel array of microfabricated pillars to maximize liquid ...