To implement high-speed and smooth start-up process of large-thrust heavy-load cylinders, a mathematical model based on the Van der Waals equation has been established compared with computational fluid dynamics (CFD) simulation results. The influence pipe diameter load mass characteristics is analyzed. results CFD are consistent maximum error occurs in gas flow at congested state. average rate two models this state 8.161kg/s 8.536kg/s respectively, an 4.4%. larger tube process, greater...

Rocket interstage separation is essential for successfully placing a payload into orbit. The substantial mass and high-speed between the stages demand an effective pneumatic device, crucial booster recovery reuse. To verify feasibility of such system developed real gas dynamic model cylinder movement process created. based on structure technical requirements single-acting also Van Der Waals equation state high-pressure gases. thermodynamic properties each cavity are analyzed. in derived...

In spool valves, there is a fit gap between and sleeve, the valve internal leakage inevitable. For problem of excessive after assembly qualified parts, taking certain type jet pipe servo as an example, probability density curve through mathematical derivation by establishing dimension chain about combining with distribution part dimensions reached. Simulation different gaps using ansys fluent, combined laws component rings in chain, plot image its are derived.

The servo actuator is a key component of the aero-engine, and often operated in extreme high-temperature conditions. Developing thermal model actuator, analyzing its heat transfer mechanisms, temperature variation laws, influencing factors great significance ensuring optimal performance under working To address this issue, theoretical method modeling proposed for actuator. Based on actual conditions lumped parameter adopted to explore exchange mechanisms. And thermodynamic mathematical...

In this study, the lubrication characteristics of a slipper bearing for axial piston pump considering oil thermal effect have been investigated. A mathematical model is developed to predict film thickness and temperature on slipper/swash plate interface under different operating conditions. Based model, parametric study conducted evaluate performance. It found that characterised by an unstable behaviour enhanced lower pressure higher rotational speed. As increases rapidly due high shaft...

The Deflector Jet Servo Valve (DJSV) holds a crucial role within the electro-hydraulic servo system, as its performance directly influences equipment reliability. DJSV operates wide temperature range, and fluctuations result in magnetomotive force variations of permanent magnets changes working air gaps, which influence operating characteristics torque motor contribute to drift. Consequently, theoretical model is proposed comprehensively analyze impact these factors on drift DJSV. results...

A thermal hydraulic model based on the lumped parameter method is presented to analyze load-carrying capacity of a slipper pair in an aviation axial-piston pump under specified operating conditions. Both theoretical and experimental results are demonstrate validity model. The illustrate that squeezing force wedge bearing main factors affect film thickness capacity. At high oil temperature load pressure, decreases with increasing clamping due combined action force, but will increase. An...

AbstractA type 304 Cu bearing stainless steel (304-Cu SS) possesses broad spectrum antibacterial properties in the laboratory environment. However, multiple bacterial species exist real life environments, and some can cause severe diseases to humans. Therefore, a study of performance 304-Cu SS different environments is importance. In this study, direct plate counting, transmission electron microscopy (TEM), confocal laser scanning microscope (SEM) were used investigate abilities three clean...

The photocurable ionogel actuator (PIA) is one of the most promising driving mechanisms for future due to its extraordinary features such as light weight, flexibility, low-energy consumption and ability work in open air. However, before benefits PIA can be effectively exploited applications, a mathematical model required enhance understanding parameters influencing electromechanical bending behavior. In this work, based on finite element method (FEM) behavior established. It assumed that...

At different working temperature, Flow coefficients of the orifices in pilot state flapper-nozzle servo valve will change due to changes hydraulic oil properties. It may pressure distribution valve, which affect dynamic performance directly. Based on test data, piecewise functions were set up describe relation between flow coefficient and number for orifices. Then combined with calculations parameters, variation null position control was simulated while temperature changed from −40°C 135°C....

A mathematical model described the thermal characteristics of an accumulator is built up based on first law thermodynamics in this paper. The dynamic temperature calculation according to finished MATLAB and simulating under system pressure pulsation transient impact conditions respectively. simulation analysis aircraft hydraulic show oil related inlet temperature, environment flow rate. This will provides theoretical fundament quantitative for systems.

Abstract Current research on pilot-operated relief valve stability is primarily conducted from the perspective of system dynamics or criteria, and most existing conclusions focus spool shape, damping hole size, pulsation frequency pump. However, essential factors pertaining to unstable vibration valves remain ambiguous. In this study, dynamic behavior a investigated using frequency-domain method. The result suggests that pressure feedback orifice vital characteristics valve. A large has low...

Describes the transfer function of a pneumatic force control system with single-acting cylinder. From experimental results an asymmetric servovalve, typical three coefficients flow gain, flow-pressure coefficient and pressure gain are obtained. Linear mathematical models introduced, then dynamic derived simplified to be third order under conditions. The relations between mechanics, parameters gains, frequency bandwidth, steady-state error also discussed. Experimental responses closed-loop presented.