bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parametric analysis of vehicle suspension based on air spring and MR damper with semi-active control
Authors: Mohammed Mortda , Alktranee Mohammed H. R. 
Published: February 2021

Abstract
Three strategies are used in this paper to investigate suspension systems behaviour. Firstly, the steel coil passive spring (conventional spring) is replaced by air spring, which comprised of an airbag, a connection pipe with a control valve, and a reservoir tank system. The influence of air spring pressure, reservoir volume and connection pipe diameter on suspension system behaviour are investigated. Secondly, a logic control scenario for the oscillation mass of air between spring airbag and the reservoir is applied by using on/off valve controller to study the controlling valve influence on the whole vehicle dynamics responses. Thirdly, the MR damper is used to introduce a variable damping coefficient as a semi-active control (skyhook) strategy of the suspension system. To represent the suspension system with the earlier mentioned strategies, a mathematical model 2-DOF for a quarter car is adopted along with governing equations of the air spring and semi-active skyhook control under the Matlab/Simulink platform. The obtained result, i.e., suspension travel displacement, body acceleration, dynamic tire force, and damper dissipation energy, are calculated in terms of RMS to show up the dynamic behaviour of suspension system considering four configurations in various control styles. The models’ responses were examined versus two road excitations pattern, including harmonic excitation and random road excitation. The results show that using air spring is considerably increased suspension quality, furthered more the suspension system is significantly enhanced when semi-active strategies are applied on air spring and MR damper.
Influence of operational parameters on the recovery rate of polyester resin surface of locally designed drum oil skimmer
Authors: Sabbar Walaa , Mohammed Bassam , Almudhaffar Mujtaba 
Published: February 2021

Abstract
The development in the industry makes the process of transferring oil between countries a necessity. There has been massive pollution in the rivers environment resulting from the leakage of oil from oil ships, the transfer of factories and workshops wastes to rivers, which posed a great danger to human life and living creatures. Therefore, it is necessary to direct attention to save the aquatic environment from pollution as the process of collecting oil manually is insufficient and slow. In the present study, the drum skimmer is manufactured with a polyester resin surface. This material is characterized by its adhesive effectiveness to liquids and availability. Operational parameters such as viscosity, temperature, and drum rotation speed are investigated using designed and fabricated drum skimmer. The experimental results showed that the fluid viscosity has a high effect on the recovery rate. Also, the recovery rate increases as the drum rotation speed increase. Moreover, the best improvement in the recovery rate is obtained at the maximum temperature.
Microstructural Modifications Produced by Nano-Metal-Phosphate Additions to Aluminum-Silicon Alloy by new System Projects
Authors: Hussein H. A. , kahdim M. j. , Atiyah A. A. 
Published: February 2021

Abstract
Al-13Si alloy microstructure affected by separate additions of Nano-Metal-Phosphate, prepared by die-casting, to synchronize refine eutectic Si and modify eutectic Al is studied. The nucleation and growth mechanisms of the Si phase are discussed via morphology and kinetics analysis. The effects point out that the measurement of eutectic Si is refined to 0.37-2.46 μm and the morphology of the large platelet eutectic Si particles had been modified into the fine fibrous shape. The technique synchronizing consequences of Nano-Metal-Phosphate is related to the AlP and Al2O3 formation. These consist of the following, the impact of Al2O3 at the interfaced between the Al segment and Si particles for obstacle the growth and enhance the refinement of the eutectic Si. The impact of AlP acts to locate of heterogeneous nucleation for eutectic Si, consisting of three aspects: interaction of dopant elements with molten Al-Si alloy to shape the nucleation site with reducing the interface energy between liquid and Si phase and increase the activation of diffusion energy throughout the liquid-solid interface. The results improve the mechanical properties of modified Al-13Si alloy and thus attributed to reducing silicone partials dimension and fibrous structure of eutectic silicon, presence of substantial AlP and Al2O3 in-situ precipitation in the eutectic location and the volume fraction increase of uniform distribution.
Wind energy applied as a sustainable technology to produce electrical energy in Basra
Authors: Jassim Ahmad K , Ateeq Adnan A 
Published: February 2021

Abstract
Wind energy is one of the main renewable energy sources that applied as sustainable technology to produce electricity. It is an environmentally friendly system that generating electricity without using any consumable materials and without producing any greenhouse gases and waste. In this research, a horizontal upwind turbine system was designed and manufactured with three blades using polyvinyl chloride PVC and high-density polyethylene HDPE, Aluminium and carbon steel material. It was applied to study the efficiency of the wind energy system in Basra to produce electricity in different airspeed and directions. The results show that the maximum airspeed in Basra is 6 m/s at a height of 4 m which produced 21 Volt and 1323 Watt. The greatest range of speed is 4-5 m/s on the south, east and north. However, the lowest airspeed is 2.45-3.5 m/s on west direction. Moreover, PVC material is not suitable to produce wind blades because it is broken fast due to a sudden change in the air direction.
Synthesis, Surface Modification and Characterization of Magnetic Fe3O4@SiO2 Core-Shell Nanoparticles
Authors: Salman D , Juzsakova T , Al-Mayyahi M A , Ákos R , Mohsen S , Ibrahim R I , Mohammed Hassan D. , Abdullah T A , Domokos E , Korim T 
Published: February 2021

Abstract
The nanoparticles of the magnetic core-shell Fe3O4@SiO2 were produced using a modified Stöber approach and functionalized with (3-amino-propyl) APTES triethoxysilane and ethylene-diamine-tetra-acetic acid (EDTA). Magnetic nano adsorbents exhibit many attractive opportunities for different purposes due to their easy removal and possibility of reusing these nanoparticles. The ligands grafting was chemically stable and did not affect the morphology or substrate structure appreciably. APTES-EDTA microspheres were formed for the removal from aqueous solution solutions of trivalent rare earth elements ions since the REEs have a strong oxygen affinity. The advantages of the SiO2 shell that covers the magnetite nanoparticles include lower specific weight and a larger grafting density compared to other surfaces, improving the resistance to acidic environments. Different techniques have described the particle size, morphology, precise surface area and surface alteration including Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and vibrating sample magnetometer (VSM). The results show that the Fe3O4 nanoparticles with an average particle size of 15 ± 3 nm were successfully synthesized at pH=11, at 25 °C temperature. Moreover, The nanoparticles prepared for Fe3O4 were coated with amorphous SiO2 and functionalized with amino and carboxylic groups.
Influence Relationship between Mathematical Model-Based Elevator braking Distance and Equilibrium Coefficient
Authors: Kuangye Niu , FengShuangchang  , Xiaoqing Chang , zhaoling Xue 
Published: February 2021

Abstract
A mathematical model was developed to compare the association between the braking distances between the unloaded upward and downward braking inspection of the elevator at 125% load, and to derive the corresponding mathematical relationship and the interrelationship between the two braking distances as a function of the equilibrium coefficient. Then, by substituting typical values for specific parameters, the corresponding conclusions were drawn.At a equilibrium coefficient between 0.4 and 0.5, the two braking distances have some similarity with some reference value.
Structure design and kinematics analysis and simulation of exercise bike type lower limb rehabilitation instrument
Authors: Lian Xun 
Published: February 2021

Abstract
This article proposes a structural design of an exercise bike-type lower limb rehabilitation device, and introduces its components and design in detail. Through the organic combination of pedal-type rehabilitation actuators and exoskeleton auxiliary fixation mechanisms, it is safe and effective to maintain or restore old Human’ lower limb exercise ability. By formulating rehabilitation training strategies and using exoskeleton assisted fixation, the training trajectory of the user’s lower limbs can be fixed and sufficient safety guarantees are provided. This design uses SolidWorks for 3D software simulation to complete the part modeling, device assembly drawing and sports simulation of the exercise bike-type lower limb rehabilitation device, which has broad development prospects and practical value.
An accurate stop control method of high-speed rolling machine for automobile production line using laser ranging and two positon close loop
Authors: Qiao Zhifeng , Ge Weimin , Zhang Haikang , Wei Huiyong 
Published: February 2021

Abstract
The high-speed rolling machine is a key equipment in the automatic production line of automobile body-in-white welding. This article focuses on analyzing a method for accurately stopping the high-speed rolling machine using laser distance measurement. Firstly, through the analysis of the movement process, the calculation method of the length of each period in the 7-stage S-type acceleration and deceleration in the movement of the high-speed rolling machine is given; secondly, the system control theory model of the measurement and control system is established to analyze the dual-position closed-loop strategy The method of realizing the accurate stopping of the high-speed rolling machine; finally, the accurate stopping control method of the high-speed rolling machine proposed in this paper was verified by building an experimental system and developing the corresponding control program.
Statics analysis and topology optimization of support base for airdrop based on ANSYS Workbench
Authors: Zhang Xiaqi , Wang Jinlong , Chen Hui , Yuan Chengdong 
Published: February 2021

Abstract
This article takes the support seat used to connect a certain airdrop system and the aircraft as the research object. According to the force of the support seat, the finite element analysis software ANSYS Workbench is used to perform static analysis on the support seat, and the overall deformation and stress of the support seat are obtained. Based on the static analysis, the topological optimization of the support base is carried out, and the original support base structure is modified according to the optimized results. Finally, under the premise of ensuring the performance requirements of the support base, the mass and volume of the optimized support base are reduced by 12.11%, meeting the design requirements of lightweight structure, and also providing a reference for future design work in this field.
Investigation on sheet flexible-die drawing process
Authors: Deli Tang , Lianfa Yang 
Published: February 2021

Abstract
The characteristics of sheet flexible-die drawing process were discussed, compared with traditional sheet drawing process, sheet flexible-die drawing process can improve the limit drawing ratio, reduce the forming force, balance the thickness distribution and enhance the formability of the sheet. In this paper, the forming principle, research status and the forming characteristics of hydroforming, viscous pressure and solid granules sheet drawing process were demonstrated. In addition, the improvement of forming quality and efficiency under the aid of ultrasonic vibration, electricity, magnetic field and the mixture of them were also reviewed.
Study on thermal characteristics of deep groove ball bearing based on Green’s Function and COMSOL
Authors: Zhang Kai , Hu Hanping , Liu Xiaojie 
Published: February 2021

Abstract
Thermal characteristics seriously affect the performance of bearing, which analyzing the temperature field of bearing is inevitable. This paper presents a better solution based on Green’s Function. It is more efficient and accurate than the integral transform method provided in current literature. The finite element method (FEM) with COMSOL is applied to simulate in the three-dimensional model. By comparing analytical solution and FEM, the tendency of temperature is reasonable. And the maximum temperature locates at the roller is 41.2476 °C . Beside, little difference in temperature between inner and outer raceway and the former is little high. Moreover, heat flux only transfers from rollers to raceway, which causes thermal load on the contact region. According to the analytical method, deep groove needs equivalent treatment to reduce error. Then 40.7995°C obtained by Green’s Function and 40.8592°C obtained by COMSOL in the same position on inner raceway. This paper mainly provides an advantage analytical method to verify the temperature field in deep groove ball bearing, and it is valuable for studying thermal reliability of bearing.
On a threshold of desorption during the pumping of a nanofluid through porous medium
Authors: Demin V A , Maryshev B S , Menshikov A I 
Published: February 2021

Abstract
The results of direct numerical simulation are intended to describe the saturation process of a nanofluid through artificial porous medium. The calculations were fulfilled using the hypothesis, which presumed the adsorptive nature of nanoparticles adhesion to the solid boundaries of pores. Mathematical statement of the problem was based on the modified MIM-model and Darcy – Boussinesq equations. The dependence of the desorption intensity on the value of filtration velocity was taken into account in the course of theoretical investigation. It was shown that this factor for concentration redistribution of the immobile impurity led to the steepening of the wave front as a function of time. Phenomenological realization of novel physical assumptions made the results of numerical modeling closer to the experimental data.
Nonlinear behavior of an insoluble surfactant partially covering liquid during the transition to equilibrium
Authors: Demin V A , Petukhov M I 
Published: February 2021

Abstract
The process of relaxation to the mechanical and thermal equilibrium state of an insoluble surfactant film partially covering liquid has been investigated theoretically by the method of direct numerical simulation. Thermometric experimental data, which describe the film dynamics along the upper free boundary of a shallow Hele – Shaw cell, are analyzed and explained. At the initial stage, the temperature along the surface is non-uniform. This distribution generates a large-scale convective motion throughout the volume. The volume of the carrying liquid is relatively small. Therefore, the mutual action of the surfactant film and moving liquid on the dynamics of each other is turned to be significant. Thermo- and concentration-capillary forces on the surface, jointly with the buoyancy one in the volume, initiate the convection but after the heating stops, the non-monotonous propagation of the thermal front can be observed on the surface for some values of governing parameters. The calculations show that the characteristics of the motion are essentially different for temperature and concentration fields. This effect can be explained by the serious distinction of the kinetic coefficients for surfactant transfer and thermal processes.
Regular flow emergence at inclined surface in a stratified turbulent medium
Authors: Ingel L Kh 
Published: February 2021

Abstract
The authors focus on the following effect: near an inclined surface in a temperature (density) stratified turbulent medium in a gravity field, a regular flow along the slope should appear. This is due to the existence of a region of weakened turbulent exchange near the solid surface, in other words, to the appearance of spatial inhomogeneities of the effective coefficient of turbulent heat transfer. In this case, horizontal components of the gradients of temperature, density and, consequently, hydrostatic pressure arise near an inclined surface. This, in turn, it leads to the emergence of an average (non-turbulent) slope current. The mentioned problem is just an example of a much wider range of phenomena – stratified flows in the gravity field, arising due to the horizontal inhomogeneity of the transfer coefficients. In conclusion, another example of such flow is given.
Numerical study of turbulent mixed convection in a rotating inter-disk cavity with axial throughflow of cooling air
Authors: Smirnov Sergei I , Abramov Alexey G , Kitanina Ekaterina E , Smirnov Evgueni M 
Published: February 2021

Abstract
The paper presents the results of eddy-resolving numerical simulation of mixed convection developing in a rapidly rotating inter-disk cavity with axial throughflow of cooling air. Under conditions of the experiments available in the literature for the case of the cavity heating from the side of the disk surfaces, the computations were performed using two methods: Implicit LES and zonal RANS/ILES, with and without taking into account the gravity effects. In case of the zonal RANS/ILES approach, the axial pipe flow and the zone of turbulent mixing of throughflow with particles of heated gas were simulated on the base of the RANS equations added by a turbulence model, whereas the major part of the buoyancy-controlled cavity flow was computed with the ILES method. The ratio of the cavity width to its outer radius was 0.13. The computations were carried out at the rotational Reynolds number equal to 2·105, if evaluated with the outer radius; the axial flow Reynolds number was 2·104. A moderate size grid used in the computations (of about 5·105 cells) provided a good resolution of quasi-laminar Ekman layers. Data on dynamics of unsteady vortex structures forming in the cavity, on characteristics of local heat transfer, as well as on effects of the gravity force action are reported. The results of computations of the time-averaged local Nusselt number on the disks surfaces are compared with measurement data; an acceptable agreement has been obtained in case of the zonal RANS/ILES approach.
Centrifugal convection in a two-layer system of reacting miscible fluids
Authors: Utochkin Vladimir , Siraev Ramil , Bratsun Dmitry 
Published: February 2021

Abstract
The authors study the effect of uniform rotation on the system of two reacting miscible liquids placed in a cylindrical Hele-Shaw cell. The cell performs a rotation with a constant velocity around the axis of symmetry resulting in a radially directed inertial field. The initial configuration of the system is statically stable and consists of two concentric layers of aqueous solutions of acid and base, which are spatially separated. When liquids are brought into contact, a neutralization reaction begins, which is accompanied by the release of salt. In this work, we obtain a system of governing equations and present the results of numerical simulation. We found that reaction-diffusion processes lead to the formation of a non-monotonic density profile with a potential well. If the rotation rate gradually increases, then a cellular convection pattern can develop in the potential well. We found that with further growth of the control parameter, the periodicity of the pattern is violated due to the influence of another convective instability, which independently develops in the domain close to the axis of rotation. The action of the inertial field results in the ejection of some convective vortices from the potential well.
Experimental study of cavitation erosion of quartz in the presence of surfactant molecules
Authors: Fattalov O O , Lyubimova T P , Rybkin K A , Lunegov I V , Kuchinskiy M O 
Published: February 2021

Abstract
The interaction of bubbles with a solid flat surface of amorphous quartz, in the presence of surfactants in water, in the presence of ultrasonic action, was experimentally investigated. The study of surface properties with the use of an atomic force microscope made it possible to study the mechanism of ultrasonic degradation of the surface of solid plates, including those with surfactants adsorbed on their surface. The experiments have shown that the changes, under the action of ultrasound, of the surface properties, in these experiments, consist in the formation of chips on the surface of quartz crystals, which leads to an increase in the average surface roughness by three times in comparison with the plates that were not subjected to ultrasonic action. Was founded that the distribution of the surfactant layer on the surface of the plates depends on the concentration of the surfactant in the solution, and its presence at the solid-liquid interface leads to a decrease in the ultrasonic erosion of the plate surface. The mechanism of heterogeneous cavitation in the presence of surfactants is to reduce the probability of interaction between an inertial cavitation bubble and a solid surface, because of which the probability of local destruction of the surface decreases.
Stability of a ferrofluid layer on a liquid substrate
Authors: Khokhryakova C A , Kolesnichenko E V 
Published: February 2021

Abstract
The stability of a horizontal magnetic fluid layer located on a liquid substrate in the alternating magnetic field orthogonal to the surface is experimentally investigated. Kerosene-based magnetite liquid stabilized with oleic acid (ferrofluid) and perfluorooctane (to create a liquid substrate) were chosen as working fluids. The presence of a free surface and interface in the magnetic fluid layer determines the influence of spatial characteristics of the system, such as the diameter of the cell and the thickness of the liquid layer, on the resonant frequency. The stability of the ferrofluid layer in an orthogonal stationary magnetic field is investigated, and the dependence of the critical field strength on the layer thickness is obtained. The dependences of intensity amplitude on the alternating magnetic field frequency are depicted for the ferrofluid layers of various initial thicknesses. The obtained stability curves show that the low frequency field (1–4 Hz) destabilizes the system, while the high frequency one (from 4 Hz and above) has a stabilizing effect.
Stability of interface between liquids with high viscosity contrast in unevenly rotating cavity
Authors: Kozlov V G , Dementieva J S , Kobeleva V S , Petuhova M A 
Published: February 2021

Abstract
The effect of modulation of the cavity rotation rate on the interface of liquids of different densities and high viscosity contrast is studied experimentally. The cavity is a short horizontal cylinder rotating around its axis. The end walls of the cavity form a narrow gap. Under uniform rotation the interface has an axisymmetric shape. With the modulation growth, the axisymmetric boundary loses stability. Instability manifests itself in the appearance of a regular quasistationary relief at the interphase. The relief excitation is associated with the Kelvin-Helmholtz instability. Tangential velocity discontinuity under modulation arises due to various interaction of liquids with the cavity end walls because of viscosity contrast. The viscosity contrast, on the one hand, is responsible for tangential velocity discontinuity; on the other, it has a significant effect on the threshold of Kelvin-Helmholtz instability. It results in decrease of stability threshold and an increase of relief wavelength.