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The residual stresses generated during the deep rolling process made on crankshafts are still not fully understood to this day. Comprehending and correctly simulating the process dynamics are key to investigate the process influence over the material microstructure. A numerical model using an explicit formulation was developed in order to accurately simulate deep rolling dynamics. Real boundary conditions,...
Piezoelectric positioning stages as control system actuator are widely used in equipment drive. In this paper, according to the physical mechanism of the piezoelectric positioning stage control system, an approximate time-domain mathematical model is established for the selection of piezoelectric positioning stage control system. The least-squares method is used to identify the parameters of the model...
The paper focuses on studying the rheological properties of different vegetable oils mixed with TiO2 nanoparticles. The rheological tests of vegetable oils are conducted on cone and plate geometry of Anton Paars rheometer (MCR-102). TiO2 nanoparticles are added in 0.5 wt%, 1 wt% and 1.5 wt% concentration. The density of nanofluids is measured from 20–80 °C, and the viscosity of nanofluids is measured...
In this study, the range of applicability for Cassie–Baxter and Wenzel equations for estimating apparent contact angle on rough surfaces is numerically discussed. To do this, circular drops with different sizes are simulated on rough surfaces with a square pillar pattern and randomly distributed cylindrical pillar. With the aid of numerical method, the local surface fraction, local length fraction...
This paper studies the effect of constant magnetic field on solidification of a conductive liquid that filled a vertical three-dimensional annulus-shaped crucible. The computational domain of the proposed geometry is a vertical annulus cavity; the inner and outer sides of the mentioned cavity have constant temperature, but top and bottom sides have been thermally insulated. The governing equations...
This work aims at discussing the cubature Kalman filter (CKF) performance when applied to a highly nonlinear problem: the artificial satellites orbit determination problem, using real global positioning system (GPS) data. The CKF is a nonlinear filter based on a third-degree spherical–radial cubature rule, which allows to numerically compute multivariate moment integrals in the Bayesian filter and...
A new semiempirical dynamic stall model is presented to predict the aerodynamic coefficients of an airfoil in unsteady conditions. The model is mainly based on two modifications on the airfoil angle of attack which introduce an equivalent angle of attack to implement in the proposed aerodynamic coefficients. The first modification includes unsteady wake effects of the airfoil in the proposed model...
In this paper, we present a numerical simulation of a laminar, steady and Newtonian flow of f-graphene nanoplatelet/water nanofluid in a new microchannel design with factors for increasing heat transfer such as presence of ribs, curves to enable satisfactory fluid mixing and changing fluid course at the inlet and exit sections. The results of this study show that Nusselt number is dependent on nanoparticles...
In this work, we study the ensemble size influence on an adaptive ensemble-based methodology for history matching of petroleum reservoirs. The assimilation scheme used is an adaptive ensemble smoother with multiple data assimilation (ES-MDA) in which both the total number of assimilations and the inflation factor of each iteration are defined automatically by the algorithm. This fact leads to the...
A confluent mixer-nozzle-shaped central plug coupled design method by using the B-spline, CFD method and revised particle swarm optimization is proposed in this paper. Then, this method is used to re-design a mixed flow exhaust system with a confluent mixer, and the performance of the re-designed model is compared with the exhaust system designed by the separated method. According to the comparison...
Attempt is made to define the shape of 2-lobe rotor-profile using three arcs. Mathematical model is proposed, and the rotor-profile is successfully parameterized in terms of two independent parameters (base and waist circle radius). Unsteady internal hydrodynamics and heat interaction of the Roots blower are captured using transient finite volume method with an adaptive mesh redistribution technique...
Most of the existing cold storages of the developing countries are dedicated toward storage of a single commodity due to which they remain underutilized for a considerable part of a year. In this paper, a conceptual design of multi-commodity cold storage has been discussed to store three high-value perishable commodities for different periods of a calendar year for round the year utilization of the...
Exploring applicable ways to control characteristics of transverse waves in periodic jungles of single-walled carbon nanotubes (SWCNTs) has been of interest to nanotechnologists and applied mechanics community. Herein, the theoretical-mechanical aspects of the influence of the longitudinal magnetic field on such highly conductive nanosystems are going to be examined. Using nonlocal Rayleigh and Timoshenko...
In the present work, energy and exergy analysis of wavy plate solar air collector (WPSAC) using a novel hybrid expert system is presented. Sugeno-based subtractive clustering method is used for extraction of cluster centers while multi-criteria ratio analysis is used for optimization and prediction of WPSAC parameter. Experimentation (270 trails) on WPSAC has been performed by varying the mass flow...
Several industrial manufacturing processes mostly depend upon measurement of gases for controlling the product quality, process control, environmental compliance and production efficiencies. We propose here unsteady natural convection radiating flow as an application of gas flow measurement through mathematical modeling based on governing fractional differential equations. The mathematical model of...
Hysteresis and significant nonlinearities in the stress–strain–temperature characteristics of shape memory alloy (SMA) actuators prevent effective utilization of these actuators and make them difficult to control. Due to these effects, the position control of SMA actuators has been a great challenge for many industrial applications. In this study, a cascade control for position tracking using torque...
Magnetorheological (MR) fluids belong to a class of controllable fluids, and the composition and concentration of its components govern its magnetorheological properties. In this study, an optimum particle loading (or mass fraction) and size of iron particles in MR fluid for use in a shear mode monotube MR damper were determined based on the damping force and off-state viscosity of synthesized MR...
Power is an important parameter for mechanical design, processing parameter optimization and motor design. A power model is established for medium equipment (aircraft, steamship, cutting machine, etc.) based on specific cutting energy and material removing rate (MRR). A group of turning experiments were carried out on aluminum alloy 6061 to validate the established power model. The specific turning...
Tailor welded blank (TWB) is a product which is developed by joining two or more than two materials having same/different thickness and/or properties before any forming process. The method to join the materials can be any of the conventional or advanced methods. TWB offers advantages like overall weight and cost reduction in a product. Despite of such advantages, the application of TWBs is partially...
This study evaluated the physico-mechanical behavior and the fracture reliability of different dental resin composites indicated for the restoration of the highly mineralized enamel. The following resin composites were tested: Concept Advanced (Vigodent), Fill Magic (Vigodent), Llis (FGM), and Natural Look (DFL); Filtek Z250 (3M ESPE) was used as a universal control. All composites were fully characterized...
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