Soret and Dufour effects on a Casson nanofluid flow past a deformable cylinder with variable characteristics and Arrhenius activation energy

In this study, the effects of variable characteristics amalgamated with chemical reaction and Arrhenius activation energy are analyzed on a two-dimensional (2D) electrically conducting radiative Casson nanoliquid flow past a deformable cylinder embedded in a porous medium. The surface of the cylinder is deformable in the radial direction i.e., the z-axis. The impression of Soret and Dufour's effects boosts the transmission of heat and mass. The flow is analyzed numerically with the combined impacts of momentum slip, convective heat, and mass conditions. A numerical solution for the system of the differential equations is attained by employing the bvp4c function in MATLAB. The dimensionless protuberant parameters are graphically illustrated and discussed for the involved profiles. It is perceived that on escalating the velocity slip parameter and porosity parameter velocity field depreciates. Also, on escalating the radiation parameter and heat transfer Biot number a prominent difference is noticed in an upsurge of the thermal field. For growing values of Brownian motion and thermophoretic parameters, temperature field augments. On escalating the curvature parameter and porosity parameter, drag force coefficient upsurges. The outcome of the Soret number, mass transfer Biot number, and activation energy parameter is quite eminent on the concentration distribution for the sheet in comparison to the deformable cylinder. A comparative analysis of the present investigation with an already published work is also added to substantiate the envisioned problem.

Distributed calculations in conjugated problems of interaction between gas flows and deformable bodies

In the mathematical modeling of conjugated problems of gas dynamics and mechanics of a deformable solid body within the partitioned approach, each of the physical problems is solved independently using the appropriate software. In the article, we consider a distributed software model built on the basis of components approach that makes it possible to connect an arbitrary number of components related to physical problems. The mathematical formulation of the problems of gas dynamics, mechanics of a deformable rigid body, as well as the boundary conditions for the conjugation of physical regions are given. The programming model is based on the ZeroC Ice middleware, which implements a distributed client-server model. As an example, we consider the problems of interaction of a shock wave with an elastically deformable obturator, consisting of two thin plates, as well as the interaction of a hollow deformable cylinder with a flow of gas. The results of numerical solution are given.

VIV Simulation of 2-D Deformable Cylinder Using Coupled FDM/FEM Method

In this work a coupled finite difference method and finite element method (FDM/FEM) is developed for numerical simulation of vortex induced vibration (VIV) phenomenon with an elastically deformable circular cylinder. The algorithm is based on a FDM with CIP (Constraint Interpolation Profile) method to fluid dynamics and a FEM to solve structural dynamics. Coupling between FDM and FEM is realized by BGS (Block Gauss-Seidel) procedure. IB (Immersed Boundary) method is applied for data transferring on the interface between fluid and structure. In this paper, numerical simulations of a 2-D circular cylinder at low Reynolds number are carried out. The effect of stiffness of the cylinder shell on the vortex shedding is investigated.

Comparative Study of Slamming Loads on Cylindrical Structures

Wave impact or slamming is a phenomenon characterized by large local pressures (10 bar or more) for very short durations (order of milliseconds). Slamming loads can cause severe damage to the structure [1]. Different numerical approximation methods are available for simulating the fluid structure interaction problems. Traditional mesh techniques use nodes and elements for approximating the continuum equations whereas particle methods like smoothed particle hydrodynamics (SPH) approximates the continuum equations using the kernel approximation technique and hence can be used for a wide range of fluid dynamics problems [2]. Since composite materials are finding increased application in the ship building industry because of their low weight and high strength properties, it is important to understand the effect of slamming loads on composite structures [3]. Normally, composite structures are made quasi-rigid to resist slamming loads, but inducing some deformability helps in reducing the incident pressures and at the same time reduces the overall weight of the structure and in turn the material cost. On the other side, inducing deformability effects the durability of the structure. In this paper, the effect of slamming on two-dimensional cylindrical structures is studied using three solvers i.e., 1) SPH solver, 2) Explicit solver and 3) Implicit solver. In the case of SPH solver, water is modelled using SPH particles and cylinder is modelled using finite elements (FE), in this case shell elements. A coupling between the SPH and FE solvers is made to simulate the fluid-structure interactions. Contact is modelled using the contact algorithms. In the case of the explicit solver, water is modelled using hexahedron or brick elements with one element in the thickness direction since symmetry is applicable along the thickness of the cylinder. Shell elements are used for modelling the cylinder and contact is handled using node to surface contact algorithm. In the case of the implicit solver, water is represented by pure two-dimensional elements. Quadratic elements are used to represent the continuum around the cylinder and triangular elements are used to represent the far off field and also to control the mesh movement. Line elements are used to represent the cylinder in this case. Two models are tested in all the three solvers: 1) rigid cylinder and 2) deformable cylinder. A comparative study of these three solvers shows that the implicit solver needed more calculation time compared to other solvers. The SPH method required less particles than the number of nodes in the other two methods to converge on the peak pressure. All three solvers show reduction of peak pressure in case of the deformable cylinder.