Effect of eccentricity on jets delivered from a primary nozzle surrounded by secondary flow is studied experimentally. The eccentricity is achieved by offsetting the annular spacing of the co-flow passage, surrounding the center nozzle generating the primary jet. This is achieved by making a base plate with its center which is offset by 2 mm in the downward direction with the center of inner nozzle

To reveal the mechanism of the friction torque on the system stability, the system nonlinear coupled dynamic model is established based on the Lagrange–Maxwell equation, in which the influence of electromechanical parameters and terminal load is considered. The end friction torque is selected as the bifurcation parameter, and its influence on the system stability is studied. At the same time, in order

Vibration isolation techniques with the use of quasi-zero Stiffness characteristics are a trending and impressive approach to attenuate undesirable vibration. The use of helical coil spring in quasi-zero stiffness vibration isolator with fluidic actuators (QZSFAs) plays a vital role to diminishing vibrational frequencies with less amplitude and adopting the system to various static loading conditions

This study presents a semi-analytical solution of the nonlinear dynamic response, shock spectrum, and dynamic buckling of a simply supported imperfect plate under various types of in-plane pulse forces. Here, the plate is modelled based on higher-order shear deformation theory (HSDT) considering the von-Kármán geometric nonlinearity. The governing nonlinear partial differential equations (NLPDEs) of

This study involves performance examination of an alpha-type novel Stirling engine and performance comparison with a V-type alpha engine. The novel engine displays very different features from the conventional V-type alpha engine. In the conventional engine, the work calculated with nodal analysis (real work) is lesser than isothermal work. In the novel engine, however, the real work becomes larger

The stochastic investigation of fracture response of centrally cracked symmetric angle ply laminated composite plates subjected to different types of biaxially applied stresses by implementing stochastic extended finite element method (SXFEM) is carried out. The second-order perturbation technique is used in the framework of well-established extended finite element method to obtain the mean and coefficient

In this paper, the displacement and deformation of a two-dimensional droplet on a vertical wall are examined using a modified pseudopotential model and imposing the multi-relaxation time into the collision term. The selected model guarantees the thermodynamic consistency adjusting proper values for the constant of the potential function k and the weighting factor for the force term, A. Also, it is

The present experimental study focuses on hydrodynamic cavitation in a transparent horizontal convergent-divergent nozzle. In the experimental section, flow first occurs through a nozzle with a half convergent angle of 21° and then a divergent angle of 8° to exit. The static pressure and the flow rate are varied to achieve different cavitation numbers in sheet mode. Pressure fluctuations are measured

The atomization of nozzles plays a crucial role in improving the efficiency of spraying for dust suppression. According to the inertia collision theory for dustfall, the droplets with small particles and high-velocity possess a greater capacity for capturing dust, which requires a relatively higher speed of spraying at the outlet of the nozzle. Along the line of dustfall-droplet-velocity-structure

This paper presents the analytical approach to investigate the nonlinear forced vibration and dynamic buckling of the variable thickness functionally graded cylindrical shells subjected to mechanical load. The nonlinear motion equations of FGM cylindrical shell with variable thickness based on classical shell theory and von Kármán geometric nonlinearity are derived. The Galerkin method and the fourth-order

In present work, numerical simulation has been performed using the volume of fluid method under steady-state condition to find the effect of various operating parameters, viz. mass flux, vapor quality and effective thermal conductivity on heat transfer coefficient using refrigerants R1234ze and R1234yf. The numerical simulation has been carried out using various turbulence models, viz. the standard

The determination of the optimized size of the support domain remains still an open question in meshless methods because there is no theoretical value or validated formula. This optimal value depends on density and distribution of points and also on the nature of the considered problem, e.g., boundary value problems, integral equations, delay-differential equations, etc. Since no theoretical value

Referring to extensive use of aluminum alloy (AA) 6061 in various types of industrial divisions, adequate knowledge of factors governing machinability aspects of AA 6061 under different heat treatment conditions (T6, T4, and T651) is important. This subject has received limited attention in the literature. Therefore, surface roughness, cutting force, tool wear as well as burr formation morphology,

This paper investigates new nonlinear mechanical model for sloshing liquid in liquid damper to mitigate vibrations. The proposed nonlinear model consists of successive multiple liquid damped masses, which are connected in series. Governing differential equations are derived and are solved using the Fourier expansion-based differential quadrature method. Verification is carried out with a single degree

The screw flight, spiral blade welded on the axial cylinder, is the core component of the screw ship unloader and can be seriously worn by the materials during long-term conveying. The damaged screw flight will make the screw ship unloader unable to unload materials or even lead to an accident. However, the existing wear model cannot be directly applied to predict the wear of the screw flight under

The high speed and high power density electromechanical system for the electric vehicle is urgently required to meet stricter emission regulation and achieve higher performance. Therefore, the electromechanical coupling effect is becoming more strengthened and may significantly degrade the performance of the motor and gear system. When gear or motor failures like gear tooth crack or rotor bar breakage

Although analysis/design of multilayer assemblies has been always an active field of research, works on the optimal design of rotating multilayer composite tubes are very limited. This paper addresses the design optimization of rotating multilayer composite tubes under internal heating and pressure. For determining the structural responses, analytical solutions are provided based on different boundary

Total knee prostheses have become established arthroplasty applications in the treatment of damaged or weakened cartilage. New implants are being produced using bio-materials which are compatible with human tissue. In the industry, these prostheses are modeled and manufactured in different design geometries. This study investigated using a novel method for an ideal geometry designed to prevent fracture

The problem deals with an investigation about propagation of Love type waves in a geometrical configuration which is composed of a viscoelastic layer sandwiched between fiber-reinforced layer and a substratum. The substratum is modeled using size-dependent consistent couple stress theory which involves a length scale parameter called characteristic length to capture the role of inner microstructures

In this paper, free vibration and transmission response for the torsional vibration of circular annular plate are presented. To the author’s knowledge, few studies can be found for the torsional vibration from wave standpoint. For this purpose, in this study, natural frequencies for the torsional vibration of annular plate with clamped–clamped and free–free boundaries are calculated. The natural frequencies

Based on judging the different stages of cavitation through high-speed photography experiments, this paper presents a strategy for analyzing the variation in noise under different cavitation stages using the BEM method and Proudman theory. A multi-field synchronous test bench for marine pump hydraulic performance, flow noise, cavitation performance and cavity distribution is built. The critical cavitation

Micromixing has a wide range of biomedical and biochemical applications. Therefore, many researchers have studied this type of microfluidic devices and have attempted to propose a design with better efficiency. Micromixers are classified as passive and active based on their mixing method (whether external energy source is used to improve mixing or not). The active micromixers have attracted the attentions

This paper proposes an adaptive attitude stabilization approach for flexible spacecraft subject to uncertainties, external disturbances, actuator saturation and unknown dynamics. The approach is synthesized based on a modified nonsingular fast terminal sliding surface (NFFTSS) and ensures fast and finite-time convergence independently of the initial states. It employs time-varying gains into the sliding

Improving strength of Al-7075 by applying severe plastic deformation (SPD) leads to a drop in material ductility. The challenge of the present study is to achieve both strength and ductility improvement in Al-7075 by a combination of dual equal channel lateral extrusion (DECLE) and aging heat treatment. The design of experiment (DOE) was also used to obtain the first-order polynomial equations in order

The free vibration of rotating functionally graded porous (FGP) circular cylindrical shell with different boundary conditions is presented analytically in this study. The porous material properties are assumed to be graded in the thickness direction of the cylindrical shell according to three types of porosity distributions. By using Love’s shell theory and Hamilton’s principle, the governing equations

Incremental forming process is a manufacturing process with many advantages, so it has received attention by many researchers, while further investigation is required for incremental forming of sandwich panels. In this study, the response surface method is employed to perform a series of experiments, and the effects of parameters, including vertical step down size, tool diameter, tool rotation speed

Under the microgravity space, many theories derived from the earth's surface become untenable, so a modified vibration equation with fractal derivative is presented in this work. With the help of the semi-inverse method, we successfully develop the fractal variational principle, which not only provides conservation laws in an energy form but also provides physical insight into the nature structures

A computational analysis was carried out on the film cooling technique over the surfaces of eroded plates. The air–water mist coolant was injected through the slotted hole. A flat plate was patterned with various erosions. The loading fraction, f = 4–16%, and blowing ratio, M = 1–1.6, were simulated to understand their influence on the mist film cooling effectiveness. The coolant injection angle or

In this paper, a new configuration is proposed for using Savonius rotors by installing two Counter-Rotating Savonius Rotors (CRSR) together. In order to study the aerodynamic performance of the CRSR turbine, 2D unsteady turbulent flow around the CRSR turbine is simulated using commercial CFD software ANSYS-Fluent16.0. Turbulence modeling is done using $$k - \omega$$ SST model. Numerical results demonstrate

The new technologies of precise positioning systems with high speed and accuracy have been in the focus of attention in the recent years. In this research, a one-axis walker type inchworm piezomotor has been designed, modeled, manufactured and characterized. Simple design, simple manufacturing and assembly processes, low manufacturing cost and also high speed and stroke are advantages of this piezomotor

This paper describes the development of a mathematical model for a beta-type Stirling engine with rhombic drive mechanism. This model is based on thermodynamics, heat transfer, mass transfer, and machine dynamics considerations, and it estimates the power output and efficiency of a beta-type Stirling engine depending on different geometric and operational variables. The model is used to conduct a parametric

In this paper, a new beam element based on third-order Reddy beam theory and modified couple stress theory is introduced for static and dynamic analyses of microbeams. The beam is resting on Kelvin–Voigt-type viscoelastic foundation. Equilibrium equations are derived by using Hamilton’s principle. Galerkin finite element method is applied to the governing equations, and shape functions of the new beam

Traditional chemical and mechanical descaling methods are expensive, inefficient and environmental pollution for removing scales in coal mine main drainage pipeline. In this study, a water jet is proposed to remove pipe scales, which can solve the inadequacies of traditional methods. Parametric optimization for water jet and descaling nozzle are analyzed. Firstly, the mechanical properties of scale

What lies at the core of an elastoplastic finite element analysis is updating the stress and its related plastic variables. The process is carried out through integrating an array of elastoplastic fundamental relationships, which are typically called constitutive equations. The complex essence of such relations as well as the usual lack of analytical closed-form solutions to these problems compels

The main objective of this study is to investigate the post-buckling thermal load–deflection path of rotating pre-twisted microblades/beams made of temperature-dependent functionally graded materials (FGMs) via nonlinear non-classical first-order shear deformation theory (FSDT). To this end, modified strain gradient theory (MSGT) as well as the von Karman geometric nonlinearity is used to develop the

The cavitation strengthening test of Aluminum lithium Alloy (8090Al–Li) was carried out with different pressure process parameters. The roughness, residual stress, and morphology of the treated samples were studied. A high dislocation density was formed in the cavitation area of the workpiece, which resulted in surfacing hardening. The cavitation effect occurred in the collapse area. It was beneficial

In this study, experimental and numerical investigations were carried out in order to determine the mechanical properties and impact response of hybrid composite laminate. The hybrid composite laminate was formed from plain woven carbon fiber reinforced epoxy (CFRE) and plain woven glass fiber reinforced epoxy (GFRE) fiber using VARTM (vacuum-assisted resin transfer molding) process. The mechanical

Fatigue failure cracking under fluctuating stressing has been a major concern of engineering for many years. Fatigue failures have become more common and thereby significantly influencing engineering design as sources of vibration and dynamic loading of components have increased. The repairs of damaged metallic structures using bonded composite patch have been proved as an economical method to increase

The turbine housing is subjected to thermal load which is essential to be taken into account in the design process. In this paper, a three-dimensional conjugate heat transfer simulation of a wastegated turbine housing has been performed. The model has been validated with data from thermocouple measurements and thermography pictures. Moreover, the effect of ventilation speed on temperature distribution

Nonlinear thermal stress analysis in a functionally graded hollow thick cylinders and spheres under the effect of high temperatures and temperature differences is considered by taking into account the material properties of the body both temperature dependent and radially graded, except Poisson’s ratio which is taken to be constant for simplicity. These conditions result in nonlinear governing differential

Residual tensile stresses generated during butt welding of plates using arc welding process lead to deformation and deterioration of fatigue strength of welded parts. This research implemented particle swarm optimization (PSO) algorithm to present optimum welding parameters to minimize the tensile residual stresses of butt-welded 304 stainless-steel plates with 4–15 mm thicknesses. A set of 32 experiments

In order to weaken the strict geometric constraint relationship between the axes of joints so as to reduce manufacturing/assembling errors of overconstrained mechanism, a configuration design methodology for single-loop non-overconstrained mechanism with inactive joints is proposed in this paper based on the screw theory. After completing analysis of degrees of freedom, the design principle and corresponding

This study aims to present a method for matching the stiffness and damping of a magneto-rheological (MR) air suspension system that will ensure optimal ride comfort of a road vehicle traveling on roads with different roughness and speeds. The authors study the matching of the damping coefficient with the damping ratio, and obtain the adjustment range of the damping coefficient. Based on the linearization

The composite materials exposed to dynamic loads may suffer damage at strength value, which is under own yield strengths. Also, improper environmental conditions accelerate the damage process. In this study, the effect of heavy chemical environments such as acid and alkaline and retaining time for these environments on flexural strength and fatigue behavior of E-glass/epoxy laminated composites was

Steam injection into milk stream is a frugal method for milk sterilization. In this paper, the steam injection into a steady liquid water stream (instead of milk stream) is experimentally investigated. A transparent mixing chamber is fabricated using which the variations in steam condensation process are photographed by a high-speed camera. The length of the steam plume in water is determined using

Generalized thermoelasticity based on Lord–Shulman theory that admits the second sound effect is developed for continuum-based modeling of the thermoelastic wave propagation in functionally graded material (FGM) rods with a variable cross-sectional area under quadratic thermal shock loading. The geometry of the problem, as well as the distribution of material properties, is defined continuously with

In this work, the behaviors of flow field and pressure fluctuations in both time and frequency domains in an axial flow pump through changing various impeller blade angles are studied and investigated by using a CFD technique. The blade angles are changed between 30°, 45o, 60o and 75o. Numerical results are validated with the experimental values, as a good agreement was found between them. The developed

The present research deals with the small and large amplitude free vibrations of thick functionally graded material (FGM) beams. Beams are resting on an elastic foundation which consists of the Winkler layer, shear layer and nonlinear springs. The effect of uniform temperature elevation is also included into the formulation. A third-order shear deformation beam theory is adopted as the basic assumption

The assessment of actual cutting forces is vital and essential task for the design and analysis of structural systems. The present study deals with experimental investigation of cutting forces during machining, considering the initial impact during the engagement of cutting tool and work piece. The cutting forces are studied on HSS tool and carbon steel work piece for various cutting parameters. Cutting

A two-way coupled Lagrangian moment approximation method for the simulation of Brownian fiber suspensions in turbulence is proposed. The flow equations are solved in an Eulerian manner. The influence of fibers on the fluid flow is taken into account by a non-Newtonian stress tensor. The fiber conformation and stresses are computed in a Lagrangian manner using the moment approximation method. The new

Our study aims to focus on the sunlight coming to the earth and the different intensity that has a strong relationship with the number of days in the year, and therefore we have taken these values throughout the year in the city of Biskra, Algeria. Based on the information we wanted to introduce some effects, for example, some atmospheric compounds and also the angle of inclination that receives sunlight

In order to reveal the influence of rotating speed on the stability of torque transmission by magnetorheological fluid, magnetic force, centrifugal force, gravity, stokes resistance and buoyancy of particles are calculated and analyzed. Besides, the rule of particles distribution is simulated by the Fluent software. On this basis, experiments are carried out based on magnetorheological transmission

Small-scale vertical axis wind turbines are good candidates for urban area use where, due to various obstacles, the airflow is turbulent. In urban areas, air velocity is mostly low and site specific, so just in a few places, like tall buildings, there are suitable airflow situation in order to use turbine, so it is a good idea to install more than one turbine in such locations. On the other hand, acoustic

Effects of nano-fluid and phase change material (PCM) were investigated experimentally on a desalination system using solar parabolic concentrator. Active distillation system has been performed with and without nano-fluid, PCM, and preheater tube. In absorbent section, PCM was used to study its effect during nighttime. Tests were carried out in different depth of distillation basin. Desalination system

Light weight and enhanced impact resistance characteristics are the principal drivers to invent advanced materials for structural and armor applications. In this article, the dynamic transient impact response of hybrid composites developed from glass fabric, polycarbonate (PC) sheet with different relative volume fractions and different stacking arrangements is discussed. The dynamic tests are performed

Light materials having high strength-to-weight ratio plays a vital role in material science especially in the field of aerospace, marine transportation, military and structural applications. Composite serves the same. Aluminium matrix composite (AMC) is the aluminium matrix which has high strength-to-weight ratio. The purpose of the work is to investigate the mechanical properties of welded AA2219

An experimental investigation is carried out on an inverse diffusion flame (IDF) burners having central air jet and being surrounded by fuel jets for an impingement heat transfer. A thorough investigation has been performed to study the effects of the diameter of air jet, orientation of fuel jets and swirl in the central air jet on an inverse diffusion flame shapes, mainly on heat transfer characteristics

This article investigates a specific type of cardiac assist device, its functional performance, and its effects on the hemodynamic patterns of blood flow through the aortic network. The aforementioned assist device can be implanted in a given patient suffering from left ventricular failure. Our previous study focused on multi-balloons device. The current cardiac assist device is composed of two semi-cylindrical

Solution-treated 7075 Al alloy is subjected to equal-channel angular pressing (ECAP) and subsequent aging treatment. Fatigue crack growth (FCG) behavior of the samples in three different states was then evaluated, namely as-received, post-ECAP naturally aged and post-ECAP artificially aged. Compared to the as-received one, it is found that ECAP and subsequent natural aging have led to a considerable

In this paper, several numerical simulations are performed to study the failure of epoxy adhesive joining composite plates. Different geometries for the joint and its edge are considered, and the effects of these geometries on the failure load are investigated. Moreover, the joints are subjected to different types of loading in order to determine the failure load. The failure theories of composite