A Proposal of Mode Polynomials for Efficient Use of Component Mode Synthesis and Methodology to Simplify the Calculation of the Connecting Beams

Analytical method using Rayleigh–Ritz method has not been widely used recently due to intensive use of finite element analysis (FEA). However as long as suitable mode functions together with component mode synthesis (CMS) can be provided, Rayleigh–Ritz method is still useful for the vibration analysis of many local structures in a ship such as tanks and supports for an equipment. In this study, polynomials which combines a simple and a fixed support have been proposed for the satisfaction of boundary conditions at a junction. Higher order polynomials have been generated using those suggested by Bhat. Since higher order polynomials used only satisfy geometrical boundary conditions, two ways are tried. One neglects moment continuity and the other satisfies moment continuity by sum of mode polynomials. Numerical analysis have been performed for typical shapes, which can generate easily more complicated structures. Comparison with FEA result shows good agreements enough to be used for practical purpose. Frequently dynamic behavior of one specific subcomponent is more concerned. In this case suitable way to estimate dynamic and static coupling of subcomponents connected to this specific subcomponent should be provided, which is not easy task. Elimination of generalized coordinates for subcomponents by mode by mode satisfaction of boundary conditions has been proposed. These results are still very useful for initial guidance.

Geometry of the Vocal Tract and Properties of Phonation near Threshold: Calculations and Measurements

In voice research, analytically-based models are efficient tools to investigate the basic physical mechanisms of phonation. Calculations based on lumped element models describe the effects of the air in the vocal tract upon threshold pressure (Pth) by its inertance. The latter depends on the geometrical boundary conditions prescribed by the vocal tract length (directly) and its cross-sectional area (inversely). Using Titze’s surface wave model (SWM) to account for the properties of the vocal folds, the influence of the vocal tract inertia is examined by two sets of calculations in combination with experiments that apply silicone-based vocal folds. In the first set, a vocal tract is constructed whose cross-sectional area is adjustable from 2.7 cm2 to 11.7 cm2. In the second set, the length of the vocal tract is varied from 4.0 cm to 59.0 cm. For both sets, the pressure and frequency data are collected and compared with calculations based on the SWM. In most cases, the measurements support the calculations; hence, the model is suited to describe and predict basic mechanisms of phonation and the inertial effects caused by a vocal tract.

Sediment-wear morphology prediction method of hydraulic machine based on differential-quadrature method

Damage caused by abrasive wear is a significant problem for hydraulic machinery in rivers with sediments. Traditional prediction methods of abrasive wear morphology with the fixed geometrical boundary are difficult to reflect the physical reality of wear because of the interaction of sediment wear, flow pattern and flow boundary. In this study, a gradual wear method based on the idea of differential-quadrature is established to investigate the asymptotic wear behavior of hydraulic machinery. The average wear rate and depth of voxels on the geometrical boundary can be obtained by the unsteady numerical simulation with RNG [Formula: see text]-[Formula: see text] turbulent model and DPM multiphase flow model. Segmented voxels of geometrical boundary of flow are reconstructed after a calculation period until the end of the total running time. So, the progressive wear morphologies of flow-passage walls can be revealed step by step. The prediction method is used to predict the wear of the clearance flow in the guide vane. The numerical results are in good agreement with the actual wear depth on the wear surfaces at the actual running time, which indicates that the specified prediction method in this paper is applicable and effective.

HYDRAULIC HEAVE – DESIGN CHARTS AND DESIGN FORMULA FOR THE REQUIRED EMBEDDED LENGTH

For the determination of the required embedded length for the safety against hydraulic heave several approximate solutions exist. However, most of these solutions do not take into account the geometrical boundary conditions such as width B and length L of the excavation as well as the thickness of the aquifer S. Thus, values obtained by such simplified approximate solutions can easily lead to either uneconomical or unsafe design. For this reason investigations on the safety against hydraulic heave have been carried out at the Chair of Geotechnical Engineering at RWTH Aachen University. Based on the results of numerous calculations dimensionless design charts have been generated. With the help of these design charts the required embedded length T can be determined quite easily taking into account the difference of the ground water level H, the Thickness of the aquifer S, the geometrical dimensions B and L of the excavation and the unit weight of submerged soil γ′. In addition to these design charts a formula has been developed. By use of this design formula the required embedded length can directly be determined taking into account the before mentioned boundary conditions.

Simulation Analysis on Wastewater Anaerobic Tank Stench in Collecting Hood with Properties of Environmental Materials

The relationship is very important between geometrical boundary parameters and mechanical ventilation airflow pattern of wastewater gas-collecting hood. Computational fluid dynamics (CFD) is an effective approach to study with standard κε turbulent model. CFD predominate results show that: the exhaust flow, tuyere pressure, velocity and pollutant concentration had a greater influence on the flow field distribution. Fiber Reinforced Polymer (FRP) stench-collecting hood can be used to anaerobic tank in long-term because of its environmental material properties for acid and wet.

Boundary Recognition by Simulating a Diffusion Process in Wireless Sensor Networks

Wireless sensor networks (WSN) are becoming increasingly promising in practice. As the predeployment design and optimization are usually unpractical in random deployment scenarios, the global optimum of the WSN’s performance is achievable only if the topology dependent self-organizing process acquires the overview of the WSN, in which the boundary is the most important. The idea of this paper comes from the fact that contours only break on the geometrical boundary and the WSN are discrete sampling systems of real environments. By simulating a diffusion process in discrete form, the end point of semi-contours suggests the boundary nodes of a WSN. The simulation cases show the algorithm is well worked in WSN with average degree higher than 10. The boundary recognition could be very valuable for other algorithms dedicated to optimize the overall performance of WSN.

Double-Skin Façade in Flotran CFD

The Aerodynamic simulation with CFD (Computational Fluid Dynamics). Double skin façade as a new segment of modern facades. The fluid flow problem is defined by the laws of conservation of mass, momentum, and energy. Geometrical parameters of element FLUID 141. Aerodynamic mode of double skin façade. Simulation model for inlet and outlet channel of double skin façade. To estimate aerodynamic entrances for inlet and outlet channel of the intermediate space for double skin facades. Aerodynamic and geometrical boundary conditions of the model. Simplified modelling of net for insect with support of real constant.

Simulation Analysis on Industrial Wastewater Adjust Pool Stench in Collecting Hood with Properties of Environmental Materials

The relationship is very important between mechanical ventilation airflow pattern and the geometrical boundary parameters of wastewater gas-collecting hood. ANSYS is an effective approach to study of the problem. With a standard κε turbulent model of CFB predominate results show that: the exhaust outlet, tuyere location of pressure, velocity and concentration had a greater influence on the flow field distribution. FRP gas-collecting hood can be used to adjust pool in long-term because of its environmental material properties for acid and wet.