Shuce Zhang¹, Xueheng Tao^1,2,3, Jinshi Lu^1,2, Xuejun Wang^1,2, ZhenhuaZeng⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.2, pp. 143-155, 2015, DOI:10.3970/fdmp.2015.011.143

Abstract Three different kinds of nozzles, normally used in industrial processes for the cleaning of material surface by means of water jets at high pressure (a Cylindrical Contracting, a Taper Contracting and Stepped nozzle), are numerically simulated with the express intent to optimize the related efficiency (cleaning effectiveness). Although some of them are found to display interesting properties, simulation results indicate that a helix nozzle displays the best jetting performances. It is shown that, as compared to improvements obtained by simply changing the jetting angle, revolving the fluid released from the helix nozzle can be used to create a grinding wheel… More >

C. S. Iorio¹, C. Perfetti¹

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.1, pp. 27-48, 2015, DOI:10.3970/fdmp.2015.011.027

Abstract In the past few years, modeling of the Acoustic StandingWaves (ASW) phenomena has become a topic of great interest due to its theoretical connections with particle/cells manipulation techniques, which represent important tools in the biotechnology field. The present paper proposes a model based on the use of moving wall boundary conditions coupled with a viscous compressible fluid in a square channel. This model successfully achieved the generation of ASWs in the square cross-section for several resonance frequencies; the corresponding acoustic potential for the fundamental resonant mode and several harmonics have also been calculated and are discussed here. More >

K. Lahmer¹, R. Bessaïh¹, A. Scipioni², M. El Ganaoui²

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.1, pp. 149-162, 2014, DOI:10.3970/fdmp.2014.010.149

Abstract This paper summarizes the outcomes of a numerical study about the phenomenon of hydrogen absorption in an axisymmetric tank geometry containing magnesium hydride heated to 300˚C and at moderate storage pressure 1 MPa. The governing equations are solved with a fully implicit finite volume numerical scheme (as implemented in the commercial software FLUENT). Different kinetic reaction equations modeling hydrogen absorption are considered and the related numerical simulations are compared with experimental results. Spatial and temporal profiles of temperature and concentration in hydride bed are plotted. More >

S. Srinivasan¹, M. Z. Saghir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.2, pp. 201-216, 2011, DOI:10.3970/fdmp.2011.007.201

Abstract CFD simulations have been made to understand the impact of the vibrations of the ISS on the thermodiffusion process. Simulations were made for two ternary hydrocarbon mixtures and one binary associated mixture. While one of the ternary mixture was at a pressure of 35 MPa, the second ternary mixture as well as the binary mixture were at a pressure of 0.101325 MPa. The analysis of the results showed that imposing the ISS vibrations had a profound effect on the Soret effect in all three systems. More precisely, in all three mixtures, a single convective flow cell is established. Such a… More >

E. Gedik¹, H.Kurt², Z.Recebli¹

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.1, pp. 23-33, 2013, DOI:10.3970/fdmp.2013.009.023

Abstract In this paper, the steady, laminar, incompressible viscous flow of an electrically conducting liquid-metal fluid is investigated numerically in a circular non-conducting pipe. The considered work fluid is Galinstan (GaInSn, i.e. Gallium-Indium-Tin). Such a liquid metal is subjected to a constant pressure gradient along the axial direction and a uniform transverse magnetic field in the spanwise direction. Numerical simulations are performed by means of the Fluent commercial software (used to solve the governing three dimensional fluid dynamics and electromagnetic field partial differential equations iteratively). The magnetic field induction, B, takes values between 0 and 1.5 T with a 0.5 T… More >

A.H. Ahadi¹, M.Z. Saghir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.4, pp. 397-422, 2012, DOI:10.3970/fdmp.2012.008.397

Abstract The numerical simulations of a thermodiffusion experiment in atmospheric pressure binary mixtures of water and isopropanol subject to micro-vibrations at reduced gravity are presented. The vibrations are induced on board ISS and FOTON-M3 due to many different reasons like crew activity, spacecraft docking or operating other experiments, etc. The effects of micro-gravity vibration were investigated in detail on all of the mixture properties. The influences of different cavity sizes as well as different signs of Soret coefficients in the solvent were considered. In this paper, the thermodiffusion experiment was subjected to two different g-jitter vibrations on board ISS and FOTON-M3… More >

A. Khourchafi¹, M. El Alami^2,3, M. Najam², M. Belhaq⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.3, pp. 323-338, 2012, DOI:10.3970/fdmp.2012.008.323

Abstract A spectral radiation study has been carried out in the framework of a statistical narrow-band model based on an inverse-tailed exponential law and the socalled P1 approximation. This new spectral formulation, which may be also regarded as a grey band formulation with a local absorption coefficient, leads to two implementation methods: a non correlated form in which the averaged formulation of the P1 approximation does not take into account the correlation between fundamental quantities and a pseudo-correlated variant consisting basically of a technique for improving the anisotropy of the radiative intensity. Real gases (H₂O, CO₂) are considered. The resulting tests… More >

D.E. Melnikov¹, V.M. Shevtsova²

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.4, pp. 329-338, 2007, DOI:10.3970/fdmp.2007.003.329

Abstract Thermocapillary convection in a long vertical liquid column (called liquid bridge) subjected to heating from above is considered for a three-dimensional Boussinesq fluid. The problem is solved numerically via finite-volume method. Full system of three dimensional Navier-Stokes equations coupled with the energy equation is solved for an incompressible fluid. Instability sets in through a wave propagating in axial direction with zero azimuthal wave number, which is a unique stable solution over a wide range of supercritical heating. Further increasing the applied temperature difference results in bifurcation of a second wave traveling azimuthally with a slightly higher frequency. The two waves… More >

Marcello Lappa¹

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.3, pp. 213-234, 2005, DOI:10.3970/fdmp.2005.001.213

Abstract The physical properties of many emulsions and metal alloys strongly depend on the multiphase morphology which is controlled to a great degree by particle-particle interaction during the related processing. In the present article significant effort is devoted to illustrate the philosophy of modeling for these phenomena and some insights into the physics. Within such a context working numerical techniques that have enjoyed a widespread use over recent years are presented and/or reviewed. Finally a focused and critical comparison of these possible approaches is reported illustrating advantages and disadvantages, strengths and weaknesses, past history and future directions. More >

K.Udaya Bhaskar^1,2, Sumit Tiwari², N. Ramakrishnan²

CMC-Computers, Materials & Continua, Vol.2, No.1, pp. 13-22, 2005, DOI:10.3970/cmc.2005.002.013

Abstract The investigation pertains to establishing a simulation methodology for understanding the separation characteristics of a typical hydrocyclone where the work was carried out using a commercially available CFD software. The studies included water flow profiles, water throughput {\&} product split, particle distribution etc. and the simulated results are further validated with suitably performed experiments. The work essentially highlights the performance of the hydrocyclone using numerical studies where water is used as a primary phase and solid particles as secondary ones. This methodology is expected to be useful in the design of hydrocyclones and optimizing the processes. More >