Mechanical

Control of an overlap-type proportional directional control valve using input shaping filter
In a hydraulic control system (herein, termed a major control loop), a proportional directional control (PDC) valve with spool position feedback may work in a minor (or inner) control loop. In this study the authors propose control designs to improve the performance of the PDC valve control loop (a minor control loop). At first, the mathematical model for the PDC valve is developed through an e...


Robust guaranteed cost H {infty} control for singular systems with multiple time delays subject to input saturation
This article investigates the robust guaranteed cost H control problem for a class of singular systems with multiple time delays subject to input saturation. The delay-dependent sufficient condition and the robust guaranteed cost H controller are proposed which guarantee that the closed-loop system is regular, impulse free and stable via Lyapunov theory, singular value theory and linear matri...
Experimental Investigations on Condensation in the Framework of ENhanced COndensers in Microgravity (ENCOM-2) Project
We report preliminary results on experimental investigations on condensation in the framework of the European Space Agency funded programme Enhanced Condensers in Microgravity (ENCOM-2) which aims at better understanding underlying phenomena during condensation. The first experiment is a study on condensation of HFE on external curvilinear surface of 15 mm height during reduced gravity experime...


Fractal Growth on the Surface of a Planet and in Orbit Around It
Fractals are defined as geometric shapes that exhibit symmetry of scale. This simply implies that fractal is a shape that it would still look the same even if somebody could zoom in on one of its parts an infinite number of times. This property is also called self-similarity with several applications including nano-pharmacology and drug nanocarriers. We are interested in the study of the proper...
Study on Heat Transfer and Flow Characteristic Under Phase-Change Process of an Acoustically Levitated Droplet
Acoustic levitation is one of the levitation technique which is expected to be used for analytical chemistry and manufacturing new materials. Thus, it is important to gather the knowledge about acoustically levitated droplet. The purpose of this study is to investigate the heat transfer and flow behavior under phase change process of an acoustically levitated droplet. The following results were...


A multiple-case assessment of product-service system leanness in UK manufacturing companies
Nowadays, manufacturing companies are moving towards lean practices and product-service system to develop their competitive ability. The purpose of this article is to present an innovative model to assess product-service system leanness incorporated with validating the model via three real-life case studies across various industries, thus improving the practical validity and relevance of the mo...
Contraction process of the circular tubes on the conical die: Theory and experiment
A new theoretical model of plastic behavior of circular metal tubes during the contraction process as a metal forming and energy absorber processes is presented in this study. Some theoretical relations are developed to predict the axial load versus the axial displacement of the contraction process, based on the theoretical model. Some quasi-static experiments were performed on circular aluminu...

Performance of a flapping foil flow energy harvester in shear flows
Through numerical simulations, we investigate the energy harvesting performance of a heaving/pitching foil in shear flow. With two-dimensional Navier–Stokes simulations, we examined the energy harvesting efficiencies of such a system in linear shear flows and compared the results with those in uniform flows. It is found that in low shear rates, the performance of the system in linear shear fl...
A review of flow-induced noise from finite wall-mounted cylinders
This paper reviews previous studies on the flow around and flow-induced noise produced by a finite wall-mounted cylinder (FWMC) of circular and square cross section. The flow around a square FWMC is somewhat understood. Conversely, the flow around a circular FWMC is not well understood, particularly because of the phenomenon of spanwise cellular shedding. The effect of the aspect ratio (the rat...

The effect of slip distribution on flow past a circular cylinder
A slip boundary has been shown to have a significant impact on flow past bluff bodies. In this work and using a circular cylinder as a model system, the effects of various slip configurations on the passing flow are investigated. a theoretical analysis using matched-asymptotic expansion is first performed in the small-Reynolds number regime following Stokes and Oseen. a slip boundary condition ...
Modeling and analysis of water-hammer in coaxial pipes
The fluid-structure interaction is studied for a system composed of two coaxial pipes in an annular geometry, for both homogeneous isotropic metal pipes and fiber-reinforced (anisotropic) pipes. Multiple waves, traveling at different speeds and amplitudes, result when a projectile impacts on the water fillinhe annular space between the pipes. In the case of carbon fiber-reinforced plastic thin ...

Experimental Evaluation of Hysteretic Behavior of Rhombic Steel Plate Dampers
Rhombic mild-steel plate damper (also named rhombic added damping and Stiffness (RADAS)) is a newly proposed and developed bending energy dissipation damper in recent years, and its mechanical properties, seismic behavior, and engineering application still need further investigations. In order to determine the basic mechanical performance of RADAS, fundamental material properties tests of three...
An Investigation into In-Cylinder Tumble Flow Characteristics with Variable Valve Lift in a Gasoline Engine
In this paper, the investigation into in-cylinder tumble flow characteristics with reduced Maximum Valve Lifts (MVL) is presented. The experimental work was conducted in a modified four-valve Spark-Ignition (SI) test engine, with optical accesses for measuring in-cylinder air motion in the vertical direction. Three different MVL of 6.8 mm, 4.0 mm and 1.7 mm were tested and Particle Image Veloci...
Transient analysis of multiple parallel cracks under anti-plane dynamic loading
The problem of a homogeneous linear elastic body containing multiple non-collinear cracks under anti-plane dynamic loading is considered in this work. The cracks are simulated by distributions of dislocations and an integral equation relating tractions on the crack planes and the dislocation densities is derived. The integral equation in the Laplace transform domain is solved by the Gaussian-Ch...
Dry sliding wear studies on SiC reinforced functionally graded aluminium matrix composites
The main aim of this study is to fabricate SiC particulate reinforced aluminum functionally graded (Al FGM) brake disc and to find the optimal friction and wear parameters using grey relational analysis. The A356-20%SiCp melt was processed using liquid metal stir casting technique followed by centrifugal casting resulting in the formation of a functionally graded Al FGM brake disc. Due to the c...