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… More >

Yuan Chen¹, Honggang Duan¹, Fei Yu¹, Xingyu Zhao¹, Han Xu¹, Jun Gao^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.2, pp. 127-142, 2015, DOI:10.3970/fdmp.2015.011.127

Abstract The dynamics of dispersed bubbles in a centrifugal separator are investigated with the aim to improve the efficiency of the system. The prototype separator consists of a rotor, a base, a diverting disc, a shaft, an oil trapping impeller, a central pipe, an inlet section for contaminated oil, an outlet section for purified oil and an air outlet. A hydrodynamic model is developed to predict the complex influence of parameters such as the centrifugal force and vacuum pressure. In particular, three different force models are selected to analyze the effect of the added mass and More >

Tomoki Hirokawa^a,*, Masahiko Murozono^a, Oleg Kabov^b,c, Haruhiko Ohta^a

Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-8, 2014, DOI:10.5098/hmt.5.17

Abstract Experiments are performed to study the liquid film behavior and corresponding local heat transfer to shear-driven liquid film flow of water in the cocurrent nitrogen gas flow. The heated channel has a cross section of 30mm in width and 5mm in height, where the bottom is operated as a heating surface of 30mm in width and 100mm in length. The heated section is divided into segments to evaluate the local heat transfer coefficients. Under most gas Reynolds numbers, the local heat transfer coefficients are increased with increasing heat flux, where three mechanisms are important; (i) More >

Tizkar B¹, A Seidavi², M Sudagar³, JT Ponce-Palafox⁴

Phyton-International Journal of Experimental Botany, Vol.83, pp. 109-116, 2014, DOI:10.32604/phyton.2014.83.109

Abstract The aim of this study was to determine the effect of a granular or liquid fertilizer on the temporal variation of phytoplankton. Enrichment of the pond water with nitrogen and phosphorus resulted in an increased gross photosynthesis and biomass of the dominant algal species. Nutrient concentrations and dilution rates can determine the temporal variation in phytoplankton abundance and primary production. The variation may be largely maintained by nutrient regeneration or turnover from different forms. More >

D.V. Jayalakshmamma¹, Dinesh P.A.², M. Sankar³, D.V. Ch,rashekhar⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.3, pp. 343-357, 2014, DOI:10.3970/fdmp.2014.010.343

Abstract We examine the motion of the two concentric immiscible liquid spheres with different viscosities in an electrically conducting fluid in the presence of transverse magnetic field. The inner sphere is assumed to move at a constant velocity. The Stoke’s equation along with the Lorentz force is considered to model the resulting fluid flow, analytical solutions being obtained by the similarity solution method in terms of modified Bessel’s functions. Streamlines related to the fluid circulation in the annulus between the two liquid spheres and inside the inner liquid sphere are presented for different combinations of the More >

A. Behjatian¹, A. Esmaeeli¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.3, pp. 299-317, 2014, DOI:10.3970/fdmp.2014.010.299

Abstract Computational studies are performed to explore the underlying physics behind the evolution of the flow field in an around a liquid jet that is immersed in another liquid and is exposed to a uniform electric field. Here the focus is on finite Reynolds and O(1) Ohnesorge number flows. This is achieved by solving the full Navier-Stokes and electric field equations using a front tracking/finite difference technique in the framework of Taylor's leaky dielectric theory. It is shown that the evolution of the flow field is determined by the relative magnitude of the ratio of the electric… More >

V. Shevtsova¹, Y. Gaponenko¹, H.C. Kuhlmann², M. Lappa³, M. Lukasser², S. Matsumoto⁴, A. Mialdun¹, J.M. Montanero⁵, K. Nishino⁶, I. Ueno⁷

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.2, pp. 197-240, 2014, DOI:10.3970/fdmp.2014.010.197

Abstract Pure surface-tension-driven flow is a unique type of flow that can be controlled through external manipulation of thermal and/or mechanical boundary conditions at the free liquid surface where the entire driving force for the convection is generated. This unique feature has been exploited in recent studies for the active control of the flow instability. The use of forced coaxial gas streams has been proposed as a way to stabilize the Marangoni convection in liquid bridges in the planned space experiment JEREMI (Japanese and European Research Experiment on Marangoni Instabilities). It is aimed at understanding the More >

Yan Shen¹, Hong Zhang^1,2,3, Hui Xu¹, Tong Bai¹, Ping Yu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.1, pp. 63-81, 2014, DOI:10.3970/fdmp.2014.010.063

Abstract Single-unit and multi-unit models of porous media (metal felts) have been used to investigate thermal fluid-structure interaction phenomena in a liquid sodium system. Micro-scale aspects have been studied via numerical simulations. The permeability of metal felts has been measured experimentally to verify the reliability of the models used. This integrated approach has allowed a proper evaluation of the interdependencies among phenomena on different scales (including relevant information on skeleton deformation and pressure drop as a function of different parameters). Pressure drop generally increases with velocity and heat flux for both laminar and turbulent flows. The More >

Davood Kalantari¹, Cameron Tropea²

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.1, pp. 37-61, 2014, DOI:10.3970/fdmp.2014.010.037

Abstract This study presents a combined experimental and theoretical investigation on the formation and spreading of a liquid film on a flat and rigid wall due to spray impact. A dual-mode phase Doppler instrument is used to characterise the spray while the average film thickness is measured using a high-speed CCD camera. The experimental results are complemented with theoretical expressions derived under the assumption that the spray is stationary. A new model for the prediction of the average wall film thickness is formulated taking into account the mean Reynolds number of the impacting drops, the flux More >

H. C. Kuhlmann¹, M. Lappa², D. Melnikov³, R. Mukin¹,F. H. Muldoon¹, D. Pushkin⁴, V. Shevtsova², I. Ueno⁵

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.1, pp. 1-10, 2014, DOI:10.3970/fdmp.2014.010.001

Abstract The rapid accumulation of particles suspended in a thermocapillary liquid bridge is planned to be investigated during the JEREMI experiment on the International Space Station scheduled for 2016. An overview is given of the current status of experimental and numerical investigations of this phenomenon. More >