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 >

Donggang Li^1,2, Alexandra Levesque², Qiang Wang^1,3,2, Agnieszka Franczak², Chun Wu¹, Jean-Paul Chopart², Jicheng He¹

CMC-Computers, Materials & Continua, Vol.30, No.3, pp. 207-218, 2012, DOI:10.3970/cmc.2012.030.207

Abstract Co/Ni bilayered films were prepared on ITO glass by electrodeposition assisted with a magnetic field up to 0.5T aligned parallel to the electrode surface. The effect of a high magnetic field annealing up to 12T on morphology and microstructure of the post-deposited films was investigated by field emission scanning electronic microscopy (FE-SEM), X-ray diffraction (XRD) and atomic force microscopy (AFM). Grain shape and grain boundary in the Co/Ni morphology were modified dramatically when the high magnetic field was applied during the annealing process. Magnetic anisotropy appeared in the films due to the preferential orientation of More >

Rashed Al-Ajmi¹, Mohamed Mosaad^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.1, pp. 51-68, 2012, DOI:10.3970/fdmp.2011.008.051

Abstract Conjugate heat transfer across a vertical solid wall separating natural convection in a cold fluid-saturated porous medium and film condensation in a saturated-vapour medium is analyzed. The analysis reveals that this thermal interaction process is mainly controlled by the thermal resistance ratio of wall to porous-side natural convection and that of condensate film to natural convection. Asymptotic and numerical results of interest are obtained for the local and mean overall Nusselt number as functions of these two thermal resistance ratios. More >

Georg F. Dietze^†, Reinhold Kneer

Frontiers in Heat and Mass Transfer, Vol.2, No.3, pp. 1-14, 2011, DOI:10.5098/hmt.v2.3.3001

Abstract Despite the use of liquid films in a wide variety of technical applications involving heat and mass transfer (e.g. nuclear reactors, cooling towers and gas turbines), where they often play an important role, the underlying momentum and heat transport processes within these thin liquid layers remain to be fully elucidated. In particular, this applies to the influence that surface waves, developing due to the film’s natural instability, exert on the mentioned processes. In this context, it has been suggested by several experimental and numerical observations that momentum and heat transfer in the capillary wave region… More >

Jing Huang, Kapil Baheti, J. K. Chen^*, Yuwen Zhang

Frontiers in Heat and Mass Transfer, Vol.2, No.1, pp. 1-10, 2011, DOI:10.5098/hmt.v2.1.3005

Abstract An axisymmetric model for thermal transport in thin metal films irradiated by an ultrashort laser pulse was developed. The superheating phenomena including preheating, melting, vaporization and re-solidification were modeled and analyzed. Together with the energy balance, nucleation dynamics was employed iteratively to track the solid-liquid interface and the gas kinetics law was used iteratively to track the liquid-vapor interface. The numerical results showed that higher laser fluence and shorter pulse width lead to higher interfacial temperature, larger melting and ablation depths. A simplified 1-D model could overestimate temperature response and ablation depth due to the More >

Dennis Bäcker¹, Andreas Ricoeur², Meinhard Kuna¹

Structural Durability & Health Monitoring, Vol.7, No.1&2, pp. 1-22, 2011, DOI:10.3970/sdhm.2011.007.001

Abstract A new sensor concept for monitoring fatigue crack growth in technical structures is presented. It allows the in-situ determination of the position of the crack tip as well as the fracture mechanical quantities. The required data are obtained from a piezoelectric polymer film, which is attached to the surface of the monitored structure. The stress intensity factors and the crack tip position are calculated from electrical potentials obtained from a sensor array by solving the non-linear inverse problem. More >

Yifan Xia, Jie Wang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.3, pp. 87-88, 2011, DOI:10.3970/icces.2011.020.087

Abstract Phase field simulation is an effective way to predict the domain evolution in ferroelectric materials. A phase field model is developed to investigate the domain structures and polarization switching in in ferroelectric thin films with deadlayers. Simulation results show that the deadlayers as well as misfit strain have a significant influence on the domain structures and polarization switching in the ferroelectric thin films. It is found that the simulated switching electric field in ferroelectric thin films decreases with the thickness of the deadlayers increasing. More >

Duning Li, Yufeng Niei?a, Xuemei Zhou, Li Cai

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.3, pp. 75-76, 2011, DOI:10.3970/icces.2011.019.075

Abstract In this study, the efficient discrete model including the resin infusion and the fiber compaction is developed to simulate the RFI (resin film infusion) process. The non-linear governing equations are derived by the Darcy's law, the Terzaghi's law and the continuity equations. The finite element method and the finite difference method are used to discretize the proposed equations, and the VOF method is used to track the filling front. Compared with the analytical results of Park, our numerical results agree well with them. Furthermore, we analyze the RFI process of BMI/G0814, and simulate the resin More >

Jia Fei, Xiu-Peng Zheng, Yan-Ping Cao^*, Xi-Qiao Feng

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 11-12, 2011, DOI:10.3970/icces.2011.018.011

Abstract Recently, a novel technique based on the wrinkling of a bilayer composite film resting on a compliant substrate was proposed to measure the elastic moduli of thin films. In this paper, this technique is studied via theoretical analysis and finite element simulations. We find that under an applied compressive strain, the composite system may exhibit various buckling modes, depending upon the applied compressive strain, the geometric and material parameters of the system. We elucidate the physical mechanisms underlying the occurrence of two most typical buckling modes from the view point of energy. When the intermediate More >

Duning Li¹, Yufeng Nie^1,2, Xuemei Zhou¹, Li Cai¹

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.2, pp. 149-166, 2011, DOI:10.3970/cmes.2011.072.149

Abstract In this study, the efficient discrete model including the resin infusion and the fiber compaction is developed to simulate the RFI (resin film infusion) process. The non-linear governing equations are derived by the Darcy's law, the Terzaghi's law and the continuity equations. The finite element method and the finite difference method are used to discretize the proposed equations, and the VOF method is used to track the filling front. Compared with the analytical results of Park, our numerical results agree well with them. Furthermore, we analyze the RFI process of BMI/G0814, and simulate the resin More >