Open Access

ARTICLE

Chekifi. T^1,2, Dennai. B¹, Khelfaoui. R¹
FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.3, pp. 205-220, 2015, DOI:10.3970/fdmp.2015.011.205
Abstract Droplet generation, splitting and sorting are investigated numerically in the framework of a VOF technique for interface tracking and a finite-volume numerical method using the commercial code FLUENT. Droplets of water-in-oil are produced by a flow focusing technique relying on the use of a microchannell equipped with an obstacle to split the droplets. The influence of several parameters potentially affecting this process is investigated parametrically towards the end of identifying "optimal" conditions for droplet breakup. Such parameters include surface tension, the capillary number and the main channel width. We show that the capillary number plays a crucial role in determining… More >

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1495

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ARTICLE

Yong Liu¹, Jianping Wei^2,3
FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.3, pp. 221-240, 2015, DOI:10.3970/fdmp.2015.011.221
Abstract Although the socalled percussion-pulsed-water jet technique is currently recognized as an effective means for breaking hard rocks, it can’t be extensively employed due to insufficient systematic research on the related flow-field structure. Considered as one of the rock breaking technologies with the highest potential of development and application, this method is characterized by water hammer effects, a high-frequency impact pressure and high-speed side flows. The typical (impact and extrusion) pistons used for this technique collide several times to form the multi-pulsed jet. Here we analyze these features through a combined experimental-numerical investigation. The number of pulses and kinetic parameters of… More >

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1209

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ARTICLE

V. N. Lad¹, Z. V. P. Murthy^1,2
FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.3, pp. 241-255, 2015, DOI:10.3970/fdmp.2015.011.241
Abstract Free liquid jets are of great technical importance in a variety of applications like ink-jet printing, glass painting, spray coating and metal cutting. Here we consider the changes induced in the dynamics of such jets by the presence of obstructions at the tube exit. Using stainless steel bars of 1.5 mm diameter as obstruction objects and aqueous solutions of glycerol of varying concentrations as working fluids, we performed experiments for different configurations, including a single rod at the centre of the tube exit, two parallel rods equidistant from the centre of the tube, and a 10 mesh screen. Images of… More >

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1767

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1366

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ARTICLE

G. Frulla¹, P. Gili¹, M. Visone², V. D’Oriano^2,3, M. Lappa⁴
FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.3, pp. 257-277, 2015, DOI:10.3970/fdmp.2015.011.257
Abstract A practical engineering approach to the design of a 60 kW wind generator with improved performances is presented. The proposed approach relies on the use of a specific, "ad hoc'' developed software, OPTIWR (Optimization Software), expressly conceived to define an "optimum'' rotor configuration in the framework of the blade-element-momentum theory. Starting from an initial input geometric configuration (corresponding to an already existing 50 kW turbine) and for given values of the wind velocity V_wind and of the advance ratio X = V_wind/ΩR (where Ω is the blade rotational speed and R is the propeller radius), this software is used to… More >

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1149

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ARTICLE

Abd el malik Bouchoucha^1,2, Rachid Bessaïh¹
FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.3, pp. 279-300, 2015, DOI:10.3970/fdmp.2015.011.279
Abstract The present paper deals with a numerical study of natural convection in a square cavity filled with a nanofluid. The left and right vertical walls of the cavity are maintained at a local temperature T_h (heat source) and a local cold temperature T_C, respectively. Horizontal walls are assumed to be adiabatic. The governing equations are discretized by using the finite volume method and solved by the SIMPLER algorithm. Our computer fortran code is validated through comparison with numerical results found in the literature. Results are presented in terms of streamlines, isotherms, local and average Nusselt numbers for the Rayleigh number… More >

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2127

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P. Pasolini^1,2, R. Savino¹, F. Franco¹, S. De Rosa¹
FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.3, pp. 301-324, 2015, DOI:10.3970/fdmp.2015.011.301
Abstract The aim of the present work is to provide a first attempt to set an aero-thermo-elastic methodology for deployable atmospheric re-entry decelerators operating at high Mach number and high dynamic pressure. Because of the severity of re-entry conditions such as high temperatures, high pressures and high velocities, the behavior of their flexible structures is a hard target to assess. In this paper a partitioned Fluid Structure Interaction (FSI) approach based on the integration of different commercial software (STAR-CCM+ and ABAQUS) is presented. In order to validate the specific codes and the overall strategy for structural and fluid dynamics analyses of… More >

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1311