International Journal of Hydromechatronics (7 papers in press)
Optimisation of nanocomposite pipes under internal fluid reinforced by FRP and CNTs under seismic load
by José António Fonseca De Oliveira Correia, Nguyen Thoi Trung, Behrooz Keshtegar
Abstract: The optimisation approach can be applied to control the dynamic response of mechanical problems. The design-based optimisation process can be provided the suitable performances of the complex engineering problem as nanocomposite pipes modelled by the Reddy theory. In this current work, a hybrid intelligent basis analytical optimisation method applied for maximizing the critical velocity under frequency constraint is presented. The adaptive dynamical harmony search (ADHS) is used in the optimisation process while a numerical approach is utilized in the analytical process. The standard deviation and dynamic bandwidth are adaptively computed utilizing iteration, the design variable minimum and maximum. Four design variables are given in this problem as length to radius ratio, thickness to radius ratio, temperature and volume percent of the carbon nanotube. The optimisation results for maximizing critical velocity are compared for the different fluid velocity at two levels of FRP layers of 1 and 2.
Keywords: optimization; adaptive dynamical harmony search; seismic load; FRP; Fluid.
Static and dynamic analysis of spur gear
by Subhransu Kumar Panda, Pradeep Kumar Mishra, Biswaranjan Patra, Subrata Kumar Panda
Abstract: The demand for high speed, enhanced performance and greater reliable of machineries is increased, prediction and control of gear defects like vibration, noise and diagnosis of same are the primary consideration. In this paper, the static and dynamic behaviour of the spur gear are modelled and analysed using SOLIDWORKS and three dimensional finite element method (ANSYS workbench), respectively. Different stress components for spur gear are evaluated with varying pressures angles, keyway types, i.e., single or double made with both square or rectangular shape and material properties. Minimum stresses are observed in the gear made of 20
Keywords: ANSYS; keyway; pressure angle; SOLIDWORKS; spur gear; stress analysis.
Seismic hydro-dynamic analysis of pipes with internal and external fluid under nanoparticles as reinforcement phase
by Mansour Bagheri, Grzegorz Lesiuk, José António Fonseca De Oliveira Correia
Abstract: One of the essential subjects for the pipeline in the sea is the existence of many earthquakes in the sea, and hence, the dynamic deflection of these structures is essential. Hydro-dynamic analysis of nanocomposite pipes with internal and external fluid is presented. The system is under the earthquake dynamic load and the final equations of are obtained utilising mathematical formulation with classic theory of shell and principle of Hamilton. Navier-Stokes relation is applied to obtain the internal and external fluid forces. Mori-Tanaka approach is utilised to calculate the effective characteristics of the pipe. The dynamic deflection is calculated utilising Newmark and differential quadrature method (DQM). The influences of different variables of nanoparticles volume fraction, boundary conditions, length to radius ratios, external and internal fluid are presented on the dynamic displacement of the system. From outcomes, it may be found that the dynamic displacement is enhanced in the existence of external and internal fluid. In addition, utilising nanoparticles in pipe decreases the dynamic displacement.
Keywords: hydrodynamic analysis; pipes; earthquake; internal and external fluid; fluid.
Optimisation of propylene conversion response by neuro-fuzzy approach
by Aiyoub Fazli Shahgoli, Yousef Zandi, Arian Heirati, Masoud Khorami, Peyman Mehrabi, Dalibor Petkovic
Abstract: Propylene polymerisation is a nonlinear process with complex phenomena during the reaction. In propylene polymerisation, first principle models are not appropriate to give an accurate behaviour of the reaction due to the difficulty of complex molecular structure. The difficulty is to determine the value distribution of several parameters. In addition, the morphological properties have also contributed to the difficulties of the model formulation. Therefore, empirical or semi-empirical model could be as an alternative to the mathematical model. To estimate the output propylene conversion response, the current study has built a procedure that simulates the output response regarding to different temperature, pressure and hydrogen concentration percentage with adaptive network-based fuzzy inference system (ANFIS) method. The outcomes have shown the effectiveness of ANFIS in the optimisation of propylene conversion response.
Keywords: polymerisation; propylene conversion; response; neuro-fuzzy; ANFIS.
Selection of the most influential parameters on vectorial crystal growth of highly oriented vertically aligned carbon nanotubes by adaptive neuro-fuzzy technique
by Maryam Safa, Masoud Ahmadi, Javad Mehrmashadi, Dalibor Petkovic, Mohammad Mohammadhassani, Yousef Zandi, Yadollah Sedghi
Abstract: The optimum raising conditions to synthesis the high crystallinity carbon nanotubes (CNTs) for improvement of their physical properties are presented in this study, thus, ANFIS has been used to optimise the most effectual characteristics for predicting the crystal growing of oriented vertically aligned carbon nanotubes (OVACNT) by discovering the subset of input characteristics whole set. ANFIS has also been applied to delineate four characteristics as: 1) vaporising time (min); 2) annealing time (AT) (min); 3) precursors concentration (mL); 4) deposition temperature (
Keywords: ANFIS; growing condition; crystalline CNTs; variable selection; explanatory variables; CVD.
Comparative assessment of hydrodynamic performance of two-dimensional Naca0012 and Naca6612 hydrofoils under different cavitation and non-cavitation conditions
by Aliakbar Ghadimi, Hassan Ghassemi
Abstract: Installation of hydrofoil on a vessel results in lift force generation, especially at high speeds, and reduces its resistance. In the current paper, hydrodynamic performance of two NACA hydrofoils is numerically assessed under cavitation and non-cavitation conditions. Simulations are conducted by Ansys-CFX software and RANS equations are solved using k- turbulence model. The obtained results are compared against available experimental data and good compliance is displayed. Results of simulations indicate that hydrodynamic forces of lift and drag of the hydrofoils vary in different operating conditions. Based on numerical findings, one may conclude that lift and drag forces of two-dimensional Naca6612 hydrofoil are larger than those of Naca0012 hydrofoil. This is true in both cavitation and non-cavitation conditions. Overall, it is also concluded that under these conditions, Naca6612 hydrofoil performs much better than Naca0012 hydrofoil, and lift-to-drag ratio of Naca6612 is larger than that of Naca0012 at all angles of attack.
Keywords: hydrofoils; Naca6612; Naca0012; computational fluid dynamics; resistance; cavitation condition; non-cavitation condition.
Seat-driver vibration parameters effect on horizontal driver acceleration and its relationship to driver mass
by Seyyed Mohammad Boluhari, Masoud Masih-Tehrani, Rambod Yahyaei, Javad Marzbanrad
Abstract: This paper studies the direct effects of acceleration transmissibility between the head and seat of the driver, such as driver mass. The six DOF, seat-driver vibration model, is considered. A refuse truck with a specific driving cycle for 20 minutes is selected to evaluate the horizontal driver vibrations. The horizontal acceleration used on the driver is due to acceleration and braking operations, and the amount is considered based on the root mean square of the vibration transfer function for 20 minutes. Besides, suitable values of the vibration parameters are obtained according to the driver mass to minimise the horizontal acceleration. A survey conducted shows that the
damping coefficient between the lower part of the drivers body and seat the most effect on the horizontal acceleration acting on the driver. A linear relation between driver mass and backrest parameters and seat pan derived. Also, polynomial equations between driver mass, seat pan, and backrest derived.
Keywords: refuse truck; horizontal acceleration; vibration transmissibility; parameter study.