Hun Jung¹, Jin Seok Kim¹, Jeong Soo Kim², Jeong Park³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.11, No.4, pp. 125-126, 2009, DOI:10.3970/icces.2009.011.125

Abstract An injector plays an important role in the process of an efficient combustion in liquid-rocket engines (LRE) because it affects the evaporation rate of liquid fuel through spatial distribution and atomization of spray droplets. This paper is focused on the injection performance of a small LRE-Injector by employing the spray characteristic parameters made up of the velocity components, mean diameter, turbulence intensity, span (width of drop size distribution), number density, and volume flux of spray droplets. An experimental investigation is carried out with the aid of a dual-mode phase Doppler anemometry (DPDA) according to the injection pressure variation and along… More >

G. El hajj Sleiman¹, G. Colomines¹, R. Deterre¹, I. Petit1, E. Leroy², S. Belhabib^1,*

Journal of Renewable Materials, Vol.6, No.3, pp. 270-276, 2018, DOI:10.7569/JRM.2017.634179

Abstract Poly(3-hydroxy butyrate)-co-(3-hydroxy valerate) (PHBV) is a biobased and biodegradable polyester. This semicrystalline bioplastic could be a good candidate for the replacement of some commodity plastics derived from oil. However, the control of the conditions of its processing in order to obtain optimal properties of the finished products remains a current research subject. The objective of this work is to better understand the crystallization under injection molding conditions by inline measurements during the process. We focused on the influence of two key processing parameters, namely, mold temperature and packing pressure. The modeling of inline temperature measurements allowed an inverse estimation of… More >

Estela Krause Sammartino^1,2,3†, María Marta Reboredo⁴, Mirta I. Aranguren^*,4

Journal of Renewable Materials, Vol.4, No.2, pp. 101-112, 2016, DOI:10.7569/JRM.2014.634144

Abstract Composites made from polypropylene (PP) and local South American fibers traditionally used in yarnderived craftsmanships, Caranday Palm, were studied regarding the effect of fiber addition, concentration and characteristics of the coupling agent (molecular weight and percentage of grafted maleic anhydride), as well as type of processing. A laboratory-scale intensive mixing followed by compression, and pilot plant twin extrusion followed by injection, were the two processes investigated. The use of the first one allowed the selection of processable formulations with high fiber concentration and a percentage of coupling agent below the surface fiber saturation. In fact, it was found that there… More >

Yaghoub Dabiri^1,3, Kevin L. Sack^1,2, Semion Shaul¹, Gabriel Acevedo-Bolton¹, Jenny S. Choy³, Ghassan S. Kassab³, Julius M. Guccione^1,*

Molecular & Cellular Biomechanics, Vol.16, No.3, pp. 185-197, 2019, DOI:10.32604/mcb.2019.07364

Abstract We hypothesized that minimally invasive injections of a softening agent at strategic locations in stiff myocardium could de-stiffen the left ventricle (LV) globally. Physics-based finite element models of the LV were created from LV echocardiography images and pressures recorded during experiments in four swine. Results confirmed animal models of LV softening by systemic agents. Regional de-stiffening of myocardium led to global de-stiffening of LV. The mathematical set up was used to design LV global de-stiffening by regional softening of myocardium. At an end diastolic pressure of 23 mmHg, when 8 ml of the free wall was covered by intramyocardial injections,… More >

Yi Xue^1,2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.4, pp. 429-441, 2017, DOI:10.3970/cmes.2017.113.429

Abstract The lack of research on the effect of diffusion on methane extraction leads to low methane concentration and low utilization. The Comsol Multiphysics software is used to solve the numerical gas and solid coupled model which considers the diffusion of coal matrix, fracture seepage, permeability evolution and coal deformation. The simulation results reveal the effect of diffusion process on methane migration. The gas diffusion rate is relatively high in the initial stage. With the increase in time, the difference between coal fractures and coal matrix blocks becomes lower and the gas diffusion rate decreases gradually. The gas seepage rate decreases… More >

Xuejuan Li^1,2, Jie Ouyang^2,3, Wen Zhou²

CMES-Computer Modeling in Engineering & Sciences, Vol.96, No.6, pp. 379-407, 2013, DOI:10.3970/cmes.2013.096.379

Abstract The three-dimensional (3D) mathematical models for thermal residual stress and warpage are proposed in injection molding, in which the temperature model is rebuilt by considering the phase-change effect to improve the computational accuracy. The 3D thermal residual stress model is transformed into the incremental displacement model so that the boundary conditions can be imposed easily. A modified finite element neural network (FENN) method is used for solving 3D warpage model based on the advantages of finite element method and neural network. The influence of phase-change on temperature is discussed. The numerical simulations of thermal residual stress and warpage are realized,… More >

Qiang Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.3, pp. 207-224, 2013, DOI:10.32604/cmes.2013.094.207

Abstract In this paper, an immersed boundary method (IBM) has been developed to simulate three-dimensional (3D) complex flows in the injection molding process, in which the irregular boundary of mould is treated by a level set function. The melt front (melt-air interface) is captured and treated using the coupled level set and volume of fluid (CLSVOF) method. The finite volume method on the nonstaggered meshes is implemented to solve the governing equations, and the melt filling process is simulated in a rectangular mould with both thick- and thin-wall sections. The numerical result shows good agreement with the available data. Finally, the… More >

Xuejun Hou^1,2, Deli Gao^1,3, Zhonghou Shen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.90, No.1, pp. 1-16, 2013, DOI:10.3970/cmes.2013.090.001

Abstract Diesel tail gas drilling (DTGD) is a type of gas drilling, which uses diesel tail gas (DTG) as a circulating medium. Its cost is slightly higher than that of air drilling, but is cheaper than those of nitrogen drilling and natural gas drilling. When the reservoir is drilled with DTG, just as nitrogen and natural gas, the DTG will prevent the burning and blasting of oil and gas in the bottom hole. In order to reduce costs, the DTG is often used in drilling the reservoir, to prevent the underground explosion. This paper analyzes the composition of the Z12V190 diesel… More >

J. Wang¹, E. Andres, P. Simacek, S.G.Advani

CMES-Computer Modeling in Engineering & Sciences, Vol.88, No.3, pp. 155-182, 2012, DOI:10.3970/cmes.2012.088.155

Abstract In Liquid Composite Molding (LCM) processes, the process design requires an infusion and venting scheme which will saturate all the empty spaces between the fibers during mold filling resulting in a composite part without voids. However, the inherent material and process variability can change the filling patterns significantly which complicate this task. The objective of this work is to develop methodologies and tools to automate infusion process design and integrate it within the CAD design environment. The methodologies and algorithms developed examine the designed part geometry and material layups for ease of manufacturing with feasible infusion schemes by accounting for… More >

Qiang Li, Jie Ouyang¹, Xuejuan Li², Guorong Wu², Binxin Yang²

CMES-Computer Modeling in Engineering & Sciences, Vol.74, No.3&4, pp. 247-268, 2011, DOI:10.3970/cmes.2011.074.247

Abstract A unified mathematical model is proposed to predict the short shot, primary and secondary gas penetration phenomenon in gas-assisted injection molding (GAIM) process, where the Cross-WLF model and two-domain modified Tait equation are employed to simulate the melt viscosity and density in the whole process, respectively. The governing equations of two-phase flows including gas, air and polymer melt are solved using finite volume method with SIMPLEC technology. At first, two kinds of U-shaped gas channels are modeled, where the shape corner and generous corner cases are studied. At last, as a case study, the short shot, primary and secondary gas… More >