Applied Mechanics and Materials Vol. 419

Abstract: As for the nucleus boiling pattern of the fuel on hot surface, the nucleus boiling mechanism, evaporation process and gas-liquid balance condition have been analyzed. Based on the model of Euler multiphase flow, mathematics model of the nucleus boiling process has been constituted. Furthermore, the nucleus boiling process has been simulated by FLUENT. And then, the study provides the theoretic foundation for the forecast of the process of fuel evaporation on hot surface through the comparative analysis between the theoretic calculation conclusion and the experiment.

Abstract: Theoretical studies have shown that the generation of hydraulic fractures reduces or even reverses the stress anisotropy between the fractures and results in increasing the complexity of fractures. A finite element model was established in which the pore pressure element was used to simulate the behavior of porous media and the pore pressure cohesive element was adopted to catch the characters of hydraulic fracture. A special fracturing manner was adopted to create complicated fracture networks by reducing or even reversing the stress anisotropy between fractures. The geometries of hydraulic fractures, strains, stresses, pore pressure distributions and fluid pressures within the fractures are obtained. The results of the model are fit well with the corresponding theoretical data. The simulation results show that the stress anisotropy is reduced resulting from the generation of the hydraulic fracture, multiple parallel transverse fractures of horizontal well further reduce or even reverse the stress anisotropy in some place of the reservoir. The simulation results validate the feasibility of the theoretical studies and the expected complex network fractures could be created by adopting the special fracturing manner.

Abstract: Insect-like flapping-wing aircraft is a research focus in the study of Micro Aerial Vehicle. In the paper, a cicada is chosen as the object, and based on the analysis of its wing, its kinematics and three-dimensional model are researched. In the study of kinematics, two softwares (Movias-pro and Photoshop) are applied, and the laws of flap and torsion movements are obtained. In the study of three-dimensional mode, the wing is scanned by the use of flat plane scanning method, and the resulting picture is vectorized. Based on the wing datum, the three-dimensional model of wing is created by the use of Pro/E. The result from the paper lays foundation for the development of cicada-like flapping-wing aircraft.

Abstract: The increased demand upon the aeroelastician to obtain the distributed aerodynamic normal force loads for arbitrary launch vehicle configurations necessitated accurate method. In this work, computational fluid dynamics (CFD) is used for the determining the distributed aerodynamic loads of an axisymmetric multistage launch vehicle in the linear angle-of-attack range. ICEM-CFD and ANSYS-FLUENT software are implemented for the meshing and computational analysis. About 2750 iterations were used for the simulation purpose. Computational results are compared to available experimental data. In general, a good result within engineering error margins is obtained.

Abstract: This work investigates the effect of surface conservation law (SCL) on the high-order implicit large eddy simulation (HILES). The HILES is developed based on a seventh-order hybrid cell-edge and cell-node dissipative compact scheme (HDCS-E8T7). According to the test of flow over a cylinder, the flowfield of HILES may be contaminated by the SCL errors. Comparing with experimental data and other numerical results, reliable solutions are obtained by the HILES satisfying the SCL.

Abstract: This paper aims to explore the dynamic behavior of the twin-lift lattice crane truss. The designs used ANSYS for finite element analysis. The situations of vibration and the resonance behavior of localization were dynamically analyzed. The results of this research could provide the engineers with useful information in understanding the dynamic vibration behavior of the crane system.

Abstract: A seepage model of producing at a constant rate, based on the three outer boundary (infinite, closed, constant value) conditions and regardless of the well-bore storage and skin effects, is established for the problem of the plane radial flow of dual permeability reservoirs. Firstly, we get dimensionless model by introducing the dimensionless variables. Second, we obtain a boundary value problem of ordinary differential equation in the Laplace space by using the Laplace transformation. Finally, we prove that the solution to the boundary value problem has similar structural formula. Therefore a new method for solving such seepage model is obtainedSimilar Constructive Method (shortened as SCM). And then, according to the modified numerical inversion formula of Stehfest, we draw the curves of bottom-hole under the three kinds of outer boundary conditions by using MATLAB.

Abstract: Aim at the installation of power equipments large size smoke duct of the offshore platform, introducing a improving method which is more easy to operate.

Abstract: Aircrafts with high aspect ratio wings are most eligible candidates for high altitude and long endurance flights. Such wings show a non-linear deformation behavior because of structural geometric non-linearity. In the present study both linear and non-linear static aeroelastic behaviors of a high aspect ratio rectangular flat plate wing are analyzed using a simplified approach. The main emphasis lies in the tremendous change of lift distribution on the flexible high aspect ratio wing when large deflections are incorporated in the static aeroelastic analysis. The computational static aeroelastic simulations are performed in the finite element method based commercial software ANSYS-14. The aerodynamic load is calculated using the strip theory. Since the aero-load changes with the twisting deformation hence a user defined script is written using ANSYS parametric design language (APDL). The computationally achieved divergence velocity results are compared with the analytical results. The results of parametric study at different flight load conditions and angles of attack have highlighted the role of geometric nonlinearities in both bending and twisting deformations. The impact of follower pressure forces on the aeroelastic response is also investigated.