2,203 Results Found

Integral squeeze film damper (ISFD) is a new type of structure that appeared on the basis of traditional squeeze film damper (SFD). Since the oil film in ISFD is a segmented structure without annular flow, the nonlinearity of the oil film force has b...

The identification accuracy of dynamic characteristics coefficients is difficult to guarantee because of the errors of the measurement system itself. A novel dynamic calibration method of measurement system for dynamic characteristics coefficients is...

The classical theory of centralized dynamic characteristics with eight coefficients is adopted for traditional journal bearings. However, under cantilevered load, distributed dynamic characteristics along the axial direction will be generated for the...

This study aims to investigate the dynamic behavior of water-lubricated stern bearings during service. A transient rotor dynamics numerical model is developed to research the effects of operating conditions and critical structural parameters on the v...

The Brayton cycle based on supercritical carbon dioxide (S-CO₂) is widely used in turbomachinery. In this paper, the rotordynamic coefficients are systematically investigated for the labyrinth seal working with S-CO₂ based on NIST REFPROP database. A...

As a critical core component in the STOVL aircrafts, the dynamic and thermal performance of the aviation dry clutch directly determines the reliability of power transmission and the precision control, especially in high relative speed engagement and...

Concerning the application of high-precision, enormous rotating equipment under harsh working conditions, the advantages of dry gas sealing technology are increasingly obvious. Herein, research on the dynamic stability of dry gas seals is reviewed ba...

This article extends the celebrated Riemann–Hilbert (RH) method equipped with mixed spectrum to a new integrable system of three-component coupled time-varying coefficient complex mKdV equations (ccmKdVEs for short) generated by the mixed spect...

The use of vertical axis wind turbines (VAWTs) in urban environments is on the rise due to their relatively smaller size, simpler design, lower manufacturing and maintenance costs, and above all, due to their omnidirectionality. The multibladed drag-...

As the market for electric vehicles grows at a remarkable rate, various models of electric vehicles are currently in development, in parallel to the commercialization of components for diverse types of power supply. Cabin heating and heat management...

In the interaction of the rolling stock and the upper structure of the railway track, intense dynamic loads occur. They have a destructive effect both on the parts of the rolling stock and on the elements of the superstructure of the track. In order...

This paper presents a stability analysis of single-channel, slow-rolling, Semi-Automatic Command to Line of Sight (SACLOS) missiles using a comparison of the Routh–Hurwitz and the Frank–Wall stability criteria and a nonlinear analysis. Be...

This study explored the influence of the surface topography of a bushing on the lubrication performance of a water-lubricated bearing. Bushing deformations were considered in the mathematical model. Theoretical calculations and experiments were perfo...

Remotely operated underwater vehicles (ROVs) have been widely used in deep-sea resource exploitation and industrial engineering operations. To perform these tasks accurately in the deep-sea environment, stable motion control has become a key area of...

The study investigated how variations in pressure ratio affect the leakage flow of a brush seal for both contact and clearance structures, in which the clearance is measured as the distance between the bristles tip and the rotor surface. This investi...

In this work, a new model to analyse the dynamic characteristic coefficient of the S-CO₂ dry gas seal was reported. Taking into account that the flow within the S-CO₂ dry gas seal is close to adiabatic flow, the impact of the temperature change on th...

The influencing characteristic for the evolution mechanism of a dynamic stall vortex structure and distributed blowing control on rotor airfoils was investigated. Based on the moving-embedded grid method, the finite volume scheme, and Roe’s FDS...

Aiming to solve the problem whereby the damping process effect is significant and difficult to measure during low-speed machining of titanium alloy thin-walled parts, the ploughing coefficient of the flank face is obtained based on the frequency-doma...

Cylinder has become an indispensable and important pneumatic actuator in the development of green production technology. The sealing performance of the cylinder directly affects its safety and reliability. Under the service environment of the cylinde...

The change in raindrop spectrum characteristics is an important factor affecting the accuracy of estimations of precipitation. The in-depth study of raindrop spectrum characteristics is of great interest for understanding precipitation process and im...

The dynamic interactions among the internal components of aero-engine main shaft bearings under unsteady-state conditions are intricate, involving clearance collisions, contact, friction, and lubrication. The dynamic characteristics of bearings signi...

Supercritical CO₂ foil bearings are promising bearing technology for supercritical CO₂ high-speed turbomachinery. The partial derivative method including complete variable perturbation of the compressible turbulent lubrication Reynolds equation is ef...

Due to the complex microscope pore structure of shale, large-scale hydraulic fracturing is required to achieve effective development, resulting in a very complicated fracturing fluid flowback characteristics. The flowback volume is time-dependent, wh...

Aerostatic spindles are indispensable in the ultra-precision manufacturing field due to their high accuracy and low friction. However, rotor manufacturing errors will affect the thickness and uniformity of the air film, thereby limiting the improveme...

The vibrating flip-flow screen (VFFS) is a high-efficiency device currently used for deep screening of moist fine-grained materials. During VFFS operation, the normal operation of the screen is affected by fatigue damage to the shear springs arranged...

Turbulence and instability problems are unavoidable challenges for fluid film bearings as rotation speed continues to rise. This paper investigates the effect of turbulence on the dynamic characteristics of two non-circular journal bearings, hybrid t...

Aiming at the problem of abnormal wear caused by the poor dynamic characteristics of aeroengine segmented annular seals, according to the hydrodynamic lubrication theory, based on the conventional structure featuring the Rayleigh step profile rectang...

This study aims to establish a test method to obtain the dynamic characteristics of hydraulic-pneumatic semi-active suspensions used in tractor cabins. Because dynamic characteristics are utilized in simulation models for developing suspension contro...

Ice accretion on wind turbine blades can significantly impact their aerodynamic performance, increasing additional load and reducing power generation. This paper utilizes numerical simulation to predict the cross-section at the blade tip of a small w...

Dynamic stall control of a S809 airfoil is numerically investigated by implementing a co-flow jet (CFJ). The numerical methods of the solver are validated by comparing results with the baseline experiment as well as a NACA 6415-based CFJ experiment,...

The wave glider is an ocean-wave-propelled autonomous marine vehicle with unique dual-body architecture, which can converse the energy obtained from the ocean wave into the forward thrust. In this paper, the dynamic models of the submerged glider bas...

In this paper, a kind of single-walled carbon nanotube nonlinear model is developed and the strongly nonlinear dynamic characteristics of such carbon nanotubes subjected to random magnetic field are studied. The nonlocal effect of the microstructure...

Evaluating meteorological dynamics is a challenging task due to the variability in hydro-climatic settings. This study is designed to assess the sensitivity of precipitation and temperature dynamics to catchment variability. The effects of catchment...

Purpose: We aim to provide a systematic methodology for the optimal design of MRD for improved damping capacity and dynamical adjustability in performing its damping function. Methods: A modified Bingham model is employed to model and simulate the MR...

To study the dynamic response of a saturated sand-underground structure system subjected to earthquakes, a series of shaking table tests with a geometric scale ratio of 1/30 were conducted. Based on the experimental acceleration records of testing so...

The vibration performance is critical to the suspension control and the torque precision of the magnetically suspended momentum flywheel (MSMW). The translational and torsional vibration of the MSMW are investigated in this article, and the damping r...

A dynamic stall will cause dramatic changes in the aerodynamic performance of the blade, resulting in a sharp increase in the blade vibration load. The bionic leading-edge airfoil with different waviness ratios, inspired by the humpback whales flippe...

Aerodynamic characteristics are of great significance to the fuel economy and handling the stability of electric vehicles. The battery pack of electric vehicles has a huge structure and is usually arranged in the chassis area of the vehicle, which in...

Given the 516 Arouca pedestrian suspension bridge’s design and characteristics, the owner, a municipality, required a set of tests in order to evaluate its aerodynamic characteristics and dynamic response, aiming at both structural safety and u...

In the practice of centrifugal compressor designing, different engineering techniques are widely used because flow motion differential equations cannot be integrated, and Computational fluid dynamics cannot resolve the problem as a whole. Engineering...

During coalbed methane (CBM) production, coal reservoir pore/fracture structure varies dynamically under the action of fluid–solid coupling. And coal reservoir permeability changes accordingly. In order to factually investigate the dynamic chan...

Identification of bearings’ stiffness and damping coefficients, which strongly affects the dynamic characteristics of rotors, is another inverse problem of Rotor Dynamics. In this paper, aiming at multi-disc and multi-span rotors, two novel alg...

The dynamic coefficients of a dry gas seal affect the dynamic characteristics of rotor-seal systems. Fluid films in a dry gas seal can be laminar, turbulent or with slip conditions, according to various operating conditions and design parameters. The...

Since the structural mechanics of the super magnetostrictive actuator (GMA) system involves problems related to viscoelastic damping materials, the fractional order is more accurate than the integer order calculus to characterize the viscoelastic fea...

Hopping dynamics in glass has been known for quite a long time. In contrast, hopping dynamics in smectic-A (SmA) and hexatic smectic-B (HexB) liquid crystals (LC) has been observed only recently. The hopping in SmA phase occurs among the smectic laye...

Wind power systems participating in primary frequency regulation have become a novel trend. In order to solve the problem of the over-speed deloading (OSD) control of wind power systems failing to provide reserved capacity for primary frequency regul...

The dynamics of flood event characteristics, such as the runoff coefficient and the recession time constant, differ in time and space, due to differences in climate, geology, and runoff generation mechanisms. This study examines the variability of ev...

Inertia effect and damping capacity, which are the basic characteristics of traditional power systems, are critical to grid frequency stability. However, the inertia and damping characteristics of grid-tied photovoltaic generation systems (GPVGS), wh...

The aerodynamic calculation model of a high-speed train on the embankment under crosswind is built according to computational fluid dynamic (CFD) theory in order to obtain the aerodynamic forces on the train, and the running process of a high-speed t...

A vibration ditching machine is a machine that can effectively reduce ditching resistance and energy consumption. In this paper, taking a self-developed, self-excited vibration ditching machine as the research object, we explore its internal dynamic...