Keyong Cheng^a,b,*, Chunzi Zhang^c, Wei Chen^a,b, Shiqiang Liang^a,†, Yongxian Guo^a,d, Xiulan Huai^a

Frontiers in Heat and Mass Transfer, Vol.3, No.3, pp. 1-6, 2012, DOI:10.5098/hmt.v3.3.3003

Abstract A film cooling method with chemical heat sink for gas turbine blades is proposed. In this method, an endothermic reaction of cooling stream occurs due to the heating from the mainstream, which leads to an improvement of film cooling effectiveness. The proposed method at different blowing ratios are computed and compared with the conventional one. The simulation result shows that due to the exsitence of the chemical heat sink the proposed method can enhance film cooling effectiveness not only in the streamwise direction, but also in the spanwise direction. More >

Annamaria Mazzia¹, Giorgio Pini¹, Flavio Sartoretto²

CMES-Computer Modeling in Engineering & Sciences, Vol.88, No.3, pp. 183-210, 2012, DOI:10.3970/cmes.2012.088.183

Abstract Pure meshless techniques are promising methods for solving Partial Differential Equations (PDE). They alleviate difficulties both in designing discretization meshes, and in refining/coarsening, a task which is demanded e.g. in adaptive strategies. Meshless Local Petrov Galerkin (MLPG) methods are pure meshless techniques that receive increasing attention. Very recently, new methods, called Direct MLPG (DMLPG), have been proposed. They rely upon approximating PDE via the Generalized Moving Least Square method. DMLPG methods alleviate some difficulties of MLPG, e.g. numerical integration of tricky, non-polynomial factors, in weak forms. DMLPG techniques require lower computational costs respect to their More >

Souli M.¹, Bouamoul A.², Nguyen-Dang T.V.³

CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.5, pp. 469-486, 2012, DOI:10.3970/cmes.2012.086.469

Abstract Protection of military vehicles against blast mine and high explosive in air is of a great concern in defence industry. Anti-Vehicle (AV) mines and Improvised Explosive Devices (IED's) are capable of inflecting damage to heavy vehicles. For the last decades, numerical simulation of blast wave propagation and its interaction with surrounding structures becomes more and more the focus of computational engineering, since experimental tests are very expensive and time consuming. This paper presents an experimental and numerical investigation of blast wave propagation in air, using an Arbitrary Lagrangian Eulerian (ALE) multi-material formulation developed in LS-DYNA… More >

M. Amdi¹, M. Souli¹, J. Hargreaves², F. Erchiqui³

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.4, pp. 329-346, 2012, DOI:10.3970/cmes.2012.085.329

Abstract Simulation of vibroacoustic problems becomes more and more the focus of engineering in the last decades for acoustic comfort in automotive industry to reduce noise and vibration inside a cabin and also in sport industry to analyze sound produced by a club impacting a golf ball to avoid unexpected noise problems during the design process. Traditionally, Finite element and Boundary element methods are used in frequency domain to model pressure noise from structure vibration in low and mid frequency range. These methods require velocity in frequency domain on the vibrating structure as boundary conditions. To… More >

Souli, M.¹, Gabrys, J.²

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.2, pp. 177-192, 2012, DOI:10.3970/cmes.2012.085.177

Abstract Bird impacts on aircraft are very common and cause significant safety threats to commercial and military aircraft. According to FAA ( Federal American Aviation) regulations, aircraft should be able to land safely following specified types of bird impact on components such as radomes, windshields, engines leading edge structures and other exposed components. Thus exposed components are required to be certified for bird impact. In order to evaluate whether the aircraft is compliant to FAA requirements, several experimental tests and numerical simulations of bird impact on components need to be preformed. This paper presents an experimental More >

C.S. Nor Azwadi¹, N.I.N. Izual²

CMES-Computer Modeling in Engineering & Sciences, Vol.84, No.6, pp. 559-574, 2012, DOI:10.3970/cmes.2012.084.559

Abstract Natural convection in a differentially heated enclosure plays vital role in engineering applications such as nuclear reactor, electronic cooling technologies, roof ventilation, etc. The developed thermal flow patterns induced by the density difference are expected to be critically dependence on the inclination angles of the cavity. Hence, thermal and fluid flow pattern inside a differentially heated side enclosure walls with various inclination angles have been investigated numerically using the mesoscale lattice Boltzmann scheme. Three different dimensionless Rayleigh numbers were used, and a dimensionless Prandtl number of 0.71 was set to simulate the circulation of air More >

Weiwei Gong, Yan Liu, Xiong Zhang, Honglei Ma

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.5, pp. 527-546, 2012, DOI:10.3970/cmes.2012.083.527

Abstract Owing to its low density and good energy absorption capability, aluminum foam is an excellent protective material for spacecraft against debris impact. However, because of its complicated microstructure, it is very difficult to generate a FEM mesh accounting for the real microstructure of the alluminum foam. On the contrary, it is very easy to model three-dimensional problems with very complicated geometry with meshfree/meshless methods. Furthermore, the material point method has obvious advantages in modeling problems involving extreme large deformation problems like hypervelocity impact problem. In this paper, a three-dimensional material point model accounting for the More >

D. S. Martínez^†, J. P. Solano, J. Pérez, A. Viedma

Frontiers in Heat and Mass Transfer, Vol.2, No.3, pp. 1-10, 2011, DOI:10.5098/hmt.v2.3.3002

Abstract Non-Newtonian flow and heat transfer in tubes of heat exchangers with reciprocating insert devices have been numerically investigated. The heat exchanger is mechanically assisted by a reciprocating cylinder, which moves the scraping rods inserted in the tubes. An array of semi-circular elements is mounted on each rod, with a pitch p=5D. These elements fit the internal diameter of the tubes. During the reciprocating motion, they scrape the inner tube wall, avoiding fouling. Additionally, the movement of the inserted device generates macroscopic displacements of the flow, which continuously mix core regions with peripheral flow. A power More >

Zheng Miao^a, Ya-Ling He^a,*, Tian-Shou Zhao^b, Wen-Quan Tao^a

Frontiers in Heat and Mass Transfer, Vol.2, No.1, pp. 1-10, 2011, DOI:10.5098/hmt.v2.1.3001

Abstract A non-isothermal two-phase mass transport model is developed in this paper to investigate the heat generation and transport phenomena in a direct methanol fuel cell with anisotropic gas diffusion layers (GDLs). Thermal contact resistances at the GDL/CL (catalyst layer) and GDL/Rib interfaces, and the deformation of GDLs are considered together with the inherent anisotropy of the GDL. Latent heat effects due to condensation/evaporation of water and methanol between liquid and gas phases are also taken into account. Formulation of the two-phase mass transport across the membrane electrode assembly (MEA) is mainly based on the classical More >

M.Souli¹, F.Erchiqui²

CMES-Computer Modeling in Engineering & Sciences, Vol.77, No.3&4, pp. 183-200, 2011, DOI:10.3970/cmes.2011.077.183

Abstract During the design process of membrane structure to resist to high pressure loading, and the characterization of hyperelastic material, a structure made up of thin rubber undergoes large deformation and rotation under high pressure loading out of high pressurized gas. Until recently, to simulate the inflation of the hyperelastic membrane, a uniform pressure based on thermodynamic model or experimental tests is applied to the structure, as boundary conditions. From a computational time point of view, this approach is very fast, since no computational fluid dynamics is involved in the simulation. However, at the late stage… More >