Hydraulic Integrated Interconnected Regenerative Suspension: Modeling and Characteristics Analysis

A novel suspension system, the hydraulic integrated interconnected regenerative suspension (HIIRS), has been proposed recently. This paper demonstrates the vibration and energy harvesting characteristics of the HIIRS. The HIIRS model is established as a set of coupled, frequency-dependent equations with the hydraulic impedance method. The mechanical–fluid boundary condition in the double-acting cylinders is modelled as an external force on the mechanical system and a moving boundary on the fluid system. By integrating the HIIRS into a half car model, its free and forced vibration analyses are conducted and compared with an equivalent traditional off-road vehicle. Results show that the natural frequency and the damping ratio of the HIIRS-equipped vehicle are within a proper range of a normal off-road vehicle. The root mean square values of the bounce and roll acceleration of the HIIRS system are, respectively, 64.62 and 11.21% lower than that of a traditional suspension. The average energy harvesting power are 186.93, 417.40 and 655.90 W at the speeds of 36, 72 and 108 km/h for an off-road vehicle on a Class-C road. The results indicate that the HIIRS system can significantly enhance the vehicle dynamics and harvest the vibration energy simultaneously.

Electromagnetic and non-Darcian effects on a micropolar non-Newtonian fluid boundary-layer flow with heat and mass transfer

The purpose of this paper is to investogate the ectromagnetic and micropolar properties on biviscosity fluid flow with heat and mass transfer through a non-Darcy porous medium. Morever, The heat source, viscous dissipation, thermal diffusion and chemical reaction are taken into consideration. The system of non linear equations which govern the motion is transformed into ordinary differential equations by using a suitable similarity transformations. These equations are solved by making use of Rung–Kutta–Merson method in a shooting and matching technique. The numerical solutions of the velocity, microtation velocity, temperature and concentration are obtained as a functions of the physical parameters of the problem. Moreover the effects of these parameters on these solutions are discussed numerically and depicted graphically. It is found that the microtation velocity increases or deceases as the electric parameter, Hartman parameter and the microrotation parameter increase. Morever, the temperature increases as Forschheimer number, Eckert number increase.

Optimal Pressure Boundary Control of Steady Multiscale Fluid-Structure Interaction Shell Model Derived from Koiter Equations

Fluid-structure interaction (FSI) problems are of great interest, due to their applicability in science and engineering. However, the coupling between large fluid domains and small moving solid walls presents numerous numerical difficulties and, in some configurations, where the thickness of the solid wall can be neglected, one can consider membrane models, which are derived from the Koiter shell equations with a reduction of the computational cost of the algorithm. With this assumption, the FSI simulation is reduced to the fluid equations on a moving mesh together with a Robin boundary condition that is imposed on the moving solid surface. In this manuscript, we are interested in the study of inverse FSI problems that aim to achieve an objective by changing some design parameters, such as forces, boundary conditions, or geometrical domain shapes. We study the inverse FSI membrane model by using an optimal control approach that is based on Lagrange multipliers and adjoint variables. In particular, we propose a pressure boundary optimal control with the purpose to control the solid deformation by changing the pressure on a fluid boundary. We report the results of some numerical tests for two-dimensional domains to demonstrate the feasibility and robustness of our method.

Optical system calibration for 3D measurements in a hydrodynamic tunnel

For non-contact 3D measurements in hydrodynamic tunnels by photogrammetry methods, it is necessary to refine the standard model of image formation in the camera by taking into account an effect of refraction of rays at the boundaries of optical media, namely, at an air-glass boundary and glass-working fluid boundary. The article presents a model of image formation for shooting in a working environment that includes various optical media and methods for calibrating an optical system for 3D measurements of the coordinates of scene objects, while taking into account the real boundaries of the optical media. Experimental results on calibrating the system of three-dimensional measurements when an object image is formed by rays passing through two optical boundaries are discussed.

The Tyrian King in MT and LXX Ezekiel 28:12b–15

The biblical prophecy in Ezekiel 28:11–19 records a dirge against the king from Tyre. While the Hebrew Masoretic Text (MT) identifies the monarch as a cherub, the Greek Septuagint (LXX) distinguishes the royal from the cherub. Scholarly debates arise as to which edition represents the more original version of the prophecy. This article aims to contribute to the debates by adopting a text-critical approach to the two variant literary editions of the dirge, comparing and analyzing their differences, while incorporating insights gleaned from the extra-biblical literature originating from the ancient Near East, Second Temple Period, and Late Antiquity. The study reaches the conclusion that the current MT, with its presentation of a fluid boundary between the mortal and divine, likely builds on a more ancient interpretation of the Tyrian king. On the other hand, while the Hebrew Vorlage of LXX Ezekiel 28:12b–15 resembles the Hebrew text of the MT, the Greek translator modifies the text via literary allusions and syntactical rearrangement, so that the final result represents a later reception that suppresses any hints at the divinity of the Tyrian ruler. The result will contribute to our understanding of the historical development of the ancient Israelite religion.

Nanoparticle Deposition of Fluoropolymer CYTOP via Holographic Femtosecond Laser Processing and Its Biochip Application

The fundamental characteristics of nanoparticle (NP) deposition of the fluoropolymer CYTOP using a femtosecond (fs) laser were investigated. In previous studies, we have demonstrated the microfluidic fabrication of CYTOP, which enables clear microscopic observation of the fluid boundary because of its low refractive index, as well as that of water. In the present work, we generated CYTOP NPs using holographic fs laser processing with a spatial light modulator to demonstrate the capabilities of this functional polymer. We established a deposition technique via five-dot parallel fs laser beam irradiation for fibrous network and monolayer structures composed of CYTOP NPs on the surface of glass slides by manipulating the various fundamental laser processing parameters. The network structure on the glass surface exhibits superhydrophobic behavior, while the monolayer structure performs almost the same wettability as that of CYTOP thin film. After an investigation of the surface features of the NPs deposited onto the glass, the combination of the holographic fs laser deposition and the removal of CYTOP NPs was used to selectively pattern CYTOP NPs on the glass slide for HeLa cell culturing. Consequently, cells were selectively cultured on the glass surface where the laser removal of deposited NPs was carried out.

Observability and unique continuation of the adjoint of a linearized simplified compressible fluid-structure model in a 2d channel.

We consider a compressible fluid structure interaction model in a 2D channel with a simplified expression of the net force acting on the structure appearing at the fluid boundary. Concerning the structure we will consider a damped Euler-Bernoulli beam located on a portion of the boundary. In the present article we establish an observability inequality for the adjoint of the linearized fluid structure interaction problem under consideration which in principle is equivalent with the null controllability of the linearized system. As a corollary of the derived observability inequality we also obtain a unique continuation property for the adjoint problem.

Experimental study of thermo-fluid boundary conditions, airflow and temperature distributions in a single aisle aircraft cabin mockup

Aircraft cabin mockup has been accepted as a benchmark tool to study the aircraft cabin environment. Some researchers used computational fluid dynamics to predict the cabin environment, but the model always needs to be validated by accurate and comprehensive experimental data obtained from the cabin mockup. This study measured thermo-fluid boundary conditions, airflow and temperature distributions by appropriate instruments in a full-scale seven-row aircraft cabin mockup. We used an improved interpolation method to obtain the airflow and temperature distributions. For airflow fields, the interpolation regions were determined based on the sampling location. For the temperature field, in addition to sampling locations, cabin wall temperatures were also needed to be set as interpolation boundary. Non-uniformity coefficient was applied to evaluate homogeneities of air supply velocities and zonal wall temperatures. The measurement error and uncertainty were quantified in detail to evaluate measurement accuracy. We found that the uncertainty of the air supply velocity measured by hot-sphere anemometers was lower than that of airflow field velocity measured by ultrasonic anemometers.