Applied Mechanics and Materials Vol. 772

Abstract: This paper analyzes the unitary tensions variation on the butterfly valve disc in different conditions and at different opening angles. It performs simulations of flow inside the valve at different times in the dynamic action of opening and closing, which derive values disc forces and tensions variation in shaft. Analyzing different shapes and design parameters, the study allows an analysis of the dynamic behavior of the disc, with implications for the optimal design of butterfly valves and closing their body.

Abstract: Natural channel have complex three dimensional flow structures particularly at the outer bank cell due to the combined effects of secondary currents and higher velocity profiles. In this paper Computational fluid dynamics is used to study the meandering bend of the Barak River. Numerical modeling is done using Reynolds averaged continuity and Navier Stokes equation. These equations are solved by finite volume method. Appropriate representation of counter-rotating secondary flow in the channel bend requires both the suitable treatment of the free water surface and a turbulence model that can resolve the anisotropy of turbulence. Hence the volume of fluid method (VOF) was used to model the free surface and reynolds stress turbulence model (RSM) has been used to close the RANS equations. Higher velocity profiles were prominent at the outer bank. Skew induced stream wise vorticity was observed close to the outer bank which confirms the existence of corner induced secondary current. The vortices formed were found to be of Prandtl’s first kind.

Abstract: In future, demand on portable electronic devices will create the requirements of enduring recharged sources of power. A non-environmental friendly conventional battery with limited lifetimes has no longer feasible option. One of the mostly used solution is the piezoelectric composite structure with sensing and also actuating capabilities, mainly as a MEMS device. The optimum between actuating and energy harvesting functions is difficult to obtain. The article is presenting a study regarding the posibility to optimize both functions, performed using an analytical model and also by simulation using a FEA model.

Abstract: This work presents the computational analysis of scramjet combustor using cavities in tandem flame holder by means of 3D. The fuel used by scramjet combustor with cavities in tandem flame holder is hydrogen, the fluid flow and the work is based on the species transport combustion with standard k-ε viscous model. The Mach number at inlet is 2.47 and stagnation temperature and static pressure for vitiated air are 1000K and 100kPa respectively. These computational analysis is mainly aimed to study the flow structure and combustion efficiency. The computational results are compared qualitatively and quantitatively with experimental results and these are agreed as well. Due to the combustion, the recirculation region behind the cavity injector becomes larger as compared to mixing case which acts as a flame holder. From the analysis, the maximum Mach number of 2.33 is observed in the recirculation areas.

Abstract: Detonation combustion wave is much more energetic combustion process in pulse detonation engine combustion system. Numerous experimental, theoretical and numerical analyses have been studied in pulse detonation engine to implement in practical propulsion system. In this present computational study the simulation was carried out for deflagration flame acceleration and deflagration to detonation transition of hydrogen air combustible mixture inside the detonation tube with and without Shchelkin spiral. A three dimensional computational analysis has been done by finite volume discretization method using ANSYS Fluent 14 CFD commercial software. The LES turbulence model with second order upwind discretization scheme was adopted with standard boundary conditions for unsteady combustion wave simulations. From the computational study it was found that intensity of detonation wave velocity and dynamic pressure is higher near to the boundary of Shchelkin spiral in detonation tube. The contour plots comparisons clearly show that deflagration flame accelerates in detonation tube as present of Shchelkin spiral. The contour plots also suggest that deflagration flame velocity and pressure are less in without Shchelkin spiral in detonation tube. The accelerating detonation waves are approximately near about Chapment-Jouguet values in detonation tube with Shchelkin spiral.

Abstract: The paper deals with assessment of oil filed data from heavy off-road vehicle. The oil sample is collected off-line and processed consequently in a tribolaboratory. We call the outcomes from tribolaboratory as oil field data. Firstly we apply selected regression functions for description of the most interesting oil particles generation. It is the vehicle engine and its metal – ferrum, lead or cooper – oil data which are explored for further utilisation. We apply and present methods of multi-variate regression analysis to model the metal – Fe and Pb – data and provide outcomes + estimations for system operation so far and also proposals for system further operation. The novelty is to providing inputs for soft failure identification, to helping to change the life cycle costing, to change the system of maintenance policy, system operation and mission planning.

Abstract: Concentration process is commonly process in industries for chemicals and products that want to reach desired amount of matter in product, so concentration process control is important to reach the desired concentrate of product.Concentration in streams are affected by physical variables around it like pressure, temperature and amount of matter that solvent in streams, so the amplitude of concentration is randomly change with time that make control process not easy.In this project controller was designed for concentration process and was implemented in real-time system that constructed to verify the response of controller, in prototype concentrated solutions-juice and sugar-used to control in it separately with water then mixed to produce juice with desired property.The Mathematical model of concentrated process was evolved and Matlab used to analyze and design control loop for these model, control algorithms used as PID & Fuzzy logic controller to build controller that achieve the specification requirements of a system process.The Fuzzy PI-controller designed to control that for characteristic of nonlinearity of real-time system, and implement simulation of control loops in LABVIEW software with appropriate interface.The DAQ hardware with LABVIEW software are used to implement the control loop that designed for real-time prototype to produce the juice with desired concentrated.

Abstract: Since formation of hydrate in deep water pipeline could cause problems such as decreasing hydrocarbon production and increasing operational cost and time, this work offers to ascertain when and where hydrate will form with respect to change in pressure and temperature in deep water gas pipeline. The pressure is relatively high in deep water pipeline, and it is entirely possible to meet the hydrate formation conditions and pose a significant operational and security challenge. The study aims to develop a correlation that will help in finding hydrate formation pressure and temperature conditions of gas mixture flowing in deep water pipeline. The correlation is based on gas hydrates formation temperature with and without concentration of inhibitors. On the basis of existing published experimental data from the work by ‘E. Dendy Sloan’ and ‘Riki Kabayashi’, a new correlation will be developed using Particle Swarm Optimization. This research provides an effective coefficients for predicting hydrate formation Pressure / Temperature conditions for deep water gas pipeline.

Abstract: Spur gear is used to transfer rotary motion between parallel shafts. The simplicity in its design is one of the advantages of the spur gear. However higher frictional force that is accumulated on the gear teeth will influence the spur gear performance. Many previous papers elaborated extensively on the contact stress in the spur gear but few of them gave the details on how friction affects the gear teeth. There are insufficient frictional effect data in the gear and thus should be regarded as an important research parameter. In this paper, the contact stress of spur gear has been evaluated with and without friction by employing the Hertz theory, AGMA standard and finite element method (FEM). The frictionless contact stress result has been validated with both the theoretical methods with minimum deviation. Frictional coefficient range of 0.0 to 0.3 was selected and the corresponding contact stress is directly proportional to the friction coefficient. The work also involves the variation of face width of the gear set under the influence of friction. The contact stress of spur gear was found to be inversely proportional to the face width.

Abstract: The time varying meshing stiffness of normal and cracked spur gears of planetary gear train is studied by applying the unit normal forces at mesh point on the face width along the line of action of the single gear tooth in FE based software Ansys Workbench 14.5. The tooth deflections due to the applied forces at one mesh point are noted and a deflection matrix is established which is solved using Matlab to get net deflection and finally the meshing stiffness of gear tooth at particular mesh point. The process is repeated for other mesh points of gear tooth by rotating it to get meshing stiffness for whole gear tooth.