G. Kosec¹, B. Šarler²

CMES-Computer Modeling in Engineering & Sciences, Vol.47, No.2, pp. 191-216, 2009, DOI:10.3970/cmes.2009.047.191

Abstract This paper explores an application of a novel mesh-free Local Radial Basis Function Collocation Method (LRBFCM) [Sarler and Vertnik (2006)] in solution of coupled heat transfer and fluid flow problems with solid-liquid phase change. The melting/freezing of a pure substance is solved in primitive variables on a fixed grid with convection suppression, proportional to the amount of the solid fraction. The involved temperature, velocity and pressure fields are represented on overlapping sub-domains through collocation by using multiquadrics Radial Basis Functions (RBF). The involved first and second derivatives of the fields are calculated from the respective derivatives of the RBF's. The… More >

G. Kosec¹, B. Šarler¹

CMES-Computer Modeling in Engineering & Sciences, Vol.25, No.3, pp. 197-208, 2008, DOI:10.3970/cmes.2008.025.197

Abstract This paper explores the application of the mesh-free Local Radial Basis Function Collocation Method (LRBFCM) in solution of coupled heat transfer and fluid flow problems in Darcy porous media. The involved temperature, velocity and pressure fields are represented on overlapping sub-domains through collocation by using multiquadrics Radial Basis Functions (RBF). The involved first and second derivatives of the fields are calculated from the respective derivatives of the RBF's. The energy and momentum equations are solved through explicit time stepping. The pressure-velocity coupling is calculated iteratively, with pressure correction, predicted from the local continuity equation violation. This formulation does not require… More >

E. Y. K. Ng¹, S. T. Tan²

CMES-Computer Modeling in Engineering & Sciences, Vol.23, No.1, pp. 13-28, 2008, DOI:10.3970/cmes.2008.023.013

Abstract Microchannels have been recognized as a very effective chemical separation and heat transfer device. The electrical double layer (EDL) effect in a micro-scale flow is however anticipated to be critical. In this paper, Nernst-Planck model (NPM), is used to predict the ion concentration distribution as it is reported to be a more appropriate model for developing microchannel flow. The governing equations are discretised for developing rectangular microchannel flows in Cartesians coordinate. An additional body force source term that is relating to the electric potential, resulted from the EDL effect is introduced in the conventional z-axis momentum equation as a body… More >

M. Perl¹, C. Levy ², V. Rallabhandy ²

CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.1, pp. 37-48, 2006, DOI:10.3970/cmes.2006.011.037

Abstract The Bauschinger Effect (BE) impact on K_IN– the combined, Mode I, 3-D Stress Intensity Factor (SIF) distributions for arrays of radial, internal, surface cracks emanating from the bore of a fully or partially autofrettaged thick-walled cylinder is investigated. A in-depth comparison between the combined SIFs for a “realistic” - Bauschinger Effect Dependent Autofrettage (BEDA) and those for an “ideal” - Bauschinger Effect Independent Autofrettage (BEIA) is performed. The 3- D finite element (FE) analysis is performed employing the submodeling technique and singular elements along the crack front. Both autofrettage residual stress fields, BEDA and BEIA, are simulated using an equivalent… More >

Xuebo Zhang^{1, 2, 3}, Zhiwei Jia^{1, 2, 3, *}

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.1, pp. 53-61, 2019, DOI:10.32604/fdmp.2019.04779

Abstract The influence of ground stress was quantitatively analyzed on coal seam gas pressure and gas content in this paper. Mining activities in coal mine can result in stress concentration in the coal (rock) body around the mining space, but porosity of the coal seam would not change too much. Therefore, gas pressure and gas content in the coal seam are slightly affected. Studies showed that the free gas was gradually transformed into adsorbed gas, and the gas adsorption volume was small, and then gas pressure increases roughly linearly when the porosity decreased because of stress influence. Additionaly, when porosity of… More >

Qiping Chen¹, Yu Liu¹, Liping Zeng¹, Qiang Xiao¹, Conghui Zhou¹, Sheng Kang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.14, No.4, pp. 281-291, 2018, DOI:10.32604/fdmp.2018.03721

Abstract The brake-by-wire system requirement is promoted owing to the development of green energy vehicle, and the brake pressure control method is needed. A control method for the master cylinder hydraulic pressure based on the sliding mode control approach is proposed to provide the Electro-Hydraulic Brake system (EHB) of electric vehicles with superior system performances. An assessment is carried out about the complex nonlinear characteristics and sensitivity to the external environment of these systems, which include illustrating the working principle of the EHB system, establishing the dynamic models of the key components of the EHB system. The sliding mode control method… More >

Hameed Muhamad¹, Simant Upreti ², Ali Lohi³, Huu Doan⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.3, pp. 111-123, 2016, DOI:10.3970/fdmp.2016.012.111

Abstract Heavy Oil is an up and coming energy resource that is aggressively being sought after as the world’s energy demand increases. As technology continues to improve, this once costly energy source is quickly becoming a more viable alternative. Vapor extraction (Vapex) process is an emerging technology for viscous oil recovery that has gained much attention in the oil industry. The vapor extraction of heavy oil system is presented to describe experimental setups and procedures used to perform different experiments of vape extraction process. The generated experimental data were used to calculate the live oil maximum interfacial solvent concentration as function… More >

Hayder A. Abdulbari ^1,2, Hassan D. Mahammed¹, Z. Hassan, Wafaa K. Mahmood³

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.2, pp. 86-101, 2016, DOI:10.3970/fdmp.2016.012.086

Abstract An experimental investigation was carried out to study the response of a turbulent pressure drop fluctuations to longitudinal groove riblets, involved two configurations being triangular and spaced triangular grooves with height 600, 800, 1000 μm and peak to peak spacing 1000 μm and 2000 μm respectively. Experiments were therefore performed at free stream velocity up to 0.44 m/sec, which were corresponding to Reynolds number (Re) 53000. The development of the obtained turbulent layer downstream of the grooves was then compared with the results from the corresponding smooth-wall case. To conclude, the effect of the spaced triangular riblets on the turbulent… More >

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 >

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 >