Uncertainty based multidisciplinary analysis (UMDA) is a methodology to quantify uncertainty on the system-level quantity of interest by propagating uncertainty within and among multiple disciplines of a system. In an industrial setting, the design of complex systems involves the collaboration of multiple and diverse teams involving high-fidelity disciplinary tools and experts. Under such scenarios

AIAA Journal, Ahead of Print.

A large space antenna structure will inevitably vibrate due to the space thermal environment and maneuver actions of the satellite. Such vibration will last continuously and affect normal function of the antenna. Therefore, a proper vibration control method is vital to keep the shape accuracy of the structure within an acceptable range. The research object of this paper is a large deployable planar

Wall pressure fluctuations beneath a boundary layer are the main cause of structural vibration for hypersonic aircraft. To accurately predict the load environment of pressure fluctuations, a measurement in a hypersonic wind tunnel was carried out to investigate the characteristics of wall pressure fluctuations generated by different flow types. In the measurement, a linear sensor array was used to

In the present study, large-eddy simulations of a three-dimensional flow around the NACA 0015 wing controlled by a dielectric-barrier-discharge (DBD) plasma actuator (PA) were conducted, and the influence of the wing tip on the flow was investigated. A half-span rectangular wing with an aspect ratio (AR) of two was selected. The Reynolds number was set to 63,000, and the angles of attack were 12 and

Recent interest in flight through gusty winds has given rise to a large body of work on discrete large-amplitude gust encounters where the magnitude of the flow disturbance is large enough to incite massive flow separation. This paper outlines and introduces work performed as part of the North Atlantic Treaty Organization’s Science and Technology Organization’s Task Group AVT-282 on the unsteady aerodynamic

The stability of a two-dimensional hypersonic flat-plate boundary layer with a shallow cavity is investigated at Mach 6 using direct numerical simulations. The boundary layer is perturbed by a single-frequency wall blowing–suction actuator. The results indicate that the second mode is damped when the cavity is placed slightly downstream of the synchronization point (SP) of mode F and mode S, whereas

Purpose This study aims to numerically investigate the flow features and mixing/combustion efficiencies in a turbulent reacting jet in cross-flow by a hybrid Eulerian-Lagrangian methodology. Design/methodology/approach A high-order hybrid solver is employed where, the velocity field is obtained by solving the Eulerian filtered compressible transport equations while the species are simulated by using

In this study, the applicability of the composite model for assessing seawater intrusion and soil salinization in coastal aquifers due to climate change was investigated. In this approach, flow in the saturated zone of a coastal aquifer is simulated using a three-dimensional saturated–unsaturated transport model and flow in the unsaturated zone between the surface and groundwater level is simulated

In this paper, the deformation of compliant microcapsules is studied in narrow constrictions using a hybrid particle-based model. The model combines the Smoothed Particle Hydrodynamic (SPH) method for modelling fluid flow and the Mass Spring Model (MSM) for simulating deformable membranes. The model is initially validated for the dynamics of microcapsules in shear flow. Then, several quantitative parameters

DOI:https://doi.org/10.1103/PhysRevE.102.059904

Simulation of pore-scale porous media flows is generally considered to be a non-trivial task due to the complicacy of geometry structures involved. In the recent decades, the mesoscopic scheme of lattice Boltzmann equation (LBE), combined with the inherent half-way (HW) bounce-back boundary method has been proved to efficiently handle those complex flows. More recently, a new mesoscopic method called

In this study, we present an immersed boundary reconstruction method for the simulation of viscous compressible flows presenting strong discontinuities in the vicinity of the immersed body. The technique we propose is based on a weighted least-square reconstruction. Its major feature is that the weights are automatically adapted to the presence of a discontinuity within the least-square stencil by

Solubilities of ternary system (KCl-SrCl2-H2O) were determined using the isothermal dissolution equilibrium method at 273 and 308 K. According to the obtained experimental results, the phase diagrams of the system at 273 and 308 K were potted respectively. The results show that the ternary system has a invariant point, two univariate solubility curves and two crystallization regions corresponding to

Characteristics of flame development and the influence of reverse-flow configuration on these characteristics few seconds after ignition are investigated experimentally. Simultaneous and high-speed OH∗ chemiluminescence and pressure measurements are performed. Methane is used as the fuel, and the fuel–air equivalence ratio is 0.7. Four experimental conditions pertaining to mean bulk flow velocities

Nanofluids are of immense importance to the researchers as they have significant uses industrially due to their high heat transfer rates. This new model is employed to examine the electroosmotic flow of magnetohydrodynamic nanofluids through an asymmetric microfluidic channel. Microchannel flow is driven by the electroosmosis and peristalsis mechanisms. Nanoparticles (copper, alumina and titania) with

Acoustic streaming effects can play an important role for promoting heat and mass transfer. Considering the viscous loss inside the viscous boundary layer on the particles surface, a numerical model for the acoustic streaming outside a two-dimensional spherical particle in a plane standing wave sound field is established, and the distribution characteristics of the acoustic streaming outside the particles

As long waves propagate over an island, wave energy can be trapped in the shallow water near the coastline due to the effect of refraction and diffraction. However, in some particular situations extremely huge near-shore waves can be excited due to the resonance of edge waves. This study focuses on the occurrence condition of the resonance phenomenon, and mainly investigates the effects of geometric

This is the first study reporting a full three-dimensional (3D) non-normal-mode onset of convection in a porous medium. In this paper, the onset of thermal convection in a vertical porous cylinder is investigated theoretically. In particular, the contribution includes the following novelties. The homogeneous cylinder has a circular cross section. The eigenvalue problem is non-separable in space because

The CaO/Ca(OH)2 thermochemical energy storage system can store heat through reversible reactions for long term and transport energy for long distance, and thus can solve the mismatching between energy supply and demand. In this study, a one-dimensional model is developed for the physical–chemical–thermal processes during the hydration reaction of CaO/Ca(OH)2 system in an indirect fixed bed reactor

We present pore-scale simulations of two-phase flows in a reconstructed fibrous porous layer. The three-dimensional microstructure of the material, a fuel cell gas diffusion layer, is acquired via X-ray computed tomography and used as input for lattice Boltzmann simulations. We perform a quantitative analysis of the multiphase pore-scale dynamics, and we identify the dominant fluid structures governing

Aero-optical reduction in flat-plate turbulent boundary layer has been widely concerned due to critical application for high-speed target-seeking vehicles. From the perspective of disciplinary intersection between aerodynamic and optical engineering, the turbulence-aberrated optical behaviour, in high-Reynolds-number supersonic freestream, is numerically investigated using the in-house code High-Order

The proposal of this paper is to study the effect of magnetic field in stabilizing the hydrodynamic flow and preventing the occurrence of back flow in the Prandtl–Hartmann boundary layer. When both of the initial tangential velocity and upstream velocity are strictly increasing in the normal variable of the boundary, and the normal component of the magnetic field at the boundary is fairly strong, we

We identify and analyze the phenomena of concentration and cavitation by studying the vanishing pressure limit of solutions to a simplified isentropic relativistic Euler equations. Firstly, both the explicit expressions and geometric properties of the rarefaction wave curve and shock wave curve based on any left state are given with the help of Lorentz invariance, and the Riemann problem for this system

This paper deals with the Cauchy problem to three-dimensional compressible viscous and heat-conducting micropolar fluid model. We establish the global existence and uniqueness of classical solution to this specific system with small initial energy. In particular, the small initial energy allows the solution to have large oscillations and initial density may contain a vacuum.

In this paper, we establish the local well-posedness of strong solutions to the three dimensional viscous non-resistive MHD system with internal surface wave in low regularity Sobolev spaces. Due to the absence of magnetic diffusion, the proof will be based on the new Stokes estimates involving in optimal surface regularity, the weighted energy estimates and the higher order horizontal regularity estimates

We consider the initial value problem of the 2D dispersive quasi-geostrophic equation. We prove the long time existence of the solution for given initial data \(\theta _0 \in H^s(\mathbb {R}^2)\) with \(s>2\). Moreover, we show that the solution converges to the corresponding linear dispersive solution \(e^{-AtR_1}\theta _0\) when the size of dispersion parameter goes to infinity.

We consider a steady, geophysical 2D fluid in a domain, and focus on its western boundary layer, which is formally governed by a variant of the Prandtl equation. By using the von Mises change of variables, we show that this equation is well-posed under the assumptions that the trace of the interior stream function is large, and variations in the coastline profile are moderate.

In this work, we consider the Dirichlet problem for a non-conservative compressible two-fluid model in three dimensions. In particular, capillary pressure is taken into account in the sense that \(P^+ - P^-=f\ne 0\) where f is assumed to be a strictly decreasing function near the equilibrium. This work aims to prove that this assumption has an essential stabilization effect on the model in bounded

We prove the existence of a semiflow selection with range the space of càglàd, i.e. left-continuous and having right-hand limits functions defined on \([0,\infty )\) and taking values in a Hilbert space. Afterwards, we apply this abstract result to the system arising from a compressible viscous fluid with a barotropic pressure of the type \(a\varrho ^{\gamma }, \gamma \ge 1\), with a viscous stress