The ferromagnetic nanofluid droplets evaporating on the photothermally heated substrate exhibits different behaviors when compared with water droplets. This paper establishes a droplet evaporation model, where simulation results of mixed mode have good agreement operated experiments. residual mass and rate at temperatures light intensities are investigated, indicating that magnetic particles promoting effect evaporation. Afterwards, periodic field has been installed, variations in...

Accurate modeling of non-equilibrium molecular motion is essential for understanding rarefied supersonic flows in the upper atmosphere. This study employs dynamics simulations to investigate atomic-scale interactions argon gas around a silicon cuboid under conditions across flow regimes. Through systematic analysis velocity distributions, collision dynamics, and interfacial heat transfer from free-molecular transitional flow, atomic mechanisms that govern rarefaction effects were uncovered....

This study proposes a new near zero-wear non-contact self-impact seal based on the passive fluid blocking principle and Tesla valve structure, which is characterised by zero-wear, long lifetime, simple structure high stability. Research shows that impact-blocking effect of three-dimensional leakage channel can realise stepwise throttling sealing medium. Furthermore, pressure, number stages spacing significantly affect leakage. Leakage be effectively controlled increasing series reducing...

The Hopkinson tension bar technique is widely used and the only method utilized to measure mechanical behaviors of materials under a high strain rate; however, many fundamental problems still exist that need be made clear, which directly link measurement accuracy. In this work, these are elaborately investigated theoretically experimentally, with aid novelly designed integrated bar. Firstly, calibration for dynamical parameters proposed experimentally obtained by one-dimension stress wave...

In this paper, the effects of surface roughness and wettability on leakage performance static seals were highlighted. The results show that rate is negatively correlated with contact pressure positively roughness. Surface affects performance. Leakage retardation achieved by modifying at interface. seal interface consists two oleophobicity surfaces exhibits an excellent performance, which reduction approximately 64%. A theoretical model based established to predict rates under varying...

To overcome the scale dependence of contact model based on statistical parameters and shortcoming that initial profile existing fractal models depends area or sampling length, a new for rough surface was established dimension $D$, roughness $G$ base size $l$ largest asperity. The asperity deformation mechanism relationship between true load were explored. variation law porosity interface real under different topographies normal forces discussed. maximum $\delta $ characterizes to compact...

This paper investigates the reliability of welded metal bellows used in mechanical seals under specified working conditions. Firstly, considering environment and structural characteristics bellows, a stress relaxation test bench was developed to obtain projectile loss data different compression loads at elevated temperatures. The creep constants for simulation were derived from experimental data, finite element analysis (FEA) conducted using Workbench loads. We found that can accurately...

The pressure expansion performance is the key and basis for diffused self-pumping hydrodynamic mechanical seal to achieve its good cooling performance, self-cleaning sealing performance. Using moment of momentum theorem Stodola's formula, pressurization effect spiral groove on fluid was analyzed, energy head equation work done by established. According principle conservation energy, Bernoulli are derived, mathematical expression conversion kinetic into hydrostatic in diffuser established,...

Welded metal bellows are an elastic element widely used in the field of mechanical seals. The main objective present study was to investigate reliability welded seals under specified working conditions. To this end, a stress relaxation test bench built obtain residual force data different compression loads high-temperature environments. Then, loss equation fitted. Moreover, failure judgment form seal is proposed. According calculation relationship between face pressure and bellows’ force,...

Inspired by liquid bridge bearings, a kind of ferrofluid (FF) bearing is proposed in this work. The contains two plates with drop FF sandwiched between them. To restrain and position the FF, cylindrical magnet implanted lower plate. carrying capacity tested compared. results indicate that both bearings can provide certain amount supporting force. For similar geometries, maximum force generated (1.60 N) about 20 times higher than (0.08 N). Moreover, due to effect magnetic field, performance...

In this study, a spiral groove liquid film vaporization model based on the viscosity–temperature equation, fluid internal friction, saturation temperature, and pressure relationship equation was established. Using multiphase flow finite volume method, influence of change in mass transfer coefficient studied. Moreover, law structural parameter changes characteristics sealing performance analyzed. The results indicate that, with an increase coefficient, average vapor phase fraction first...

Abstract As a key basic component for leakage prevention in rotating machinery, research on the reliability of mechanical seals has always been focus theoretical and practical investigations. A evaluation method dynamic pressure seal based liquid film vaporization phase transition is proposed. To investigate affect mass transfer coefficient transition, model hydrodynamic face established. The working condition parameters groove structure are selected experimental testing. evaporation...

Abstract The optimal texture shape considering surface roughness is determined by solving the average Reynolds equation, selecting Jakobsson-Floberg-Olsson boundary conditions, and using a genetic algorithm. effects of as indicated combined root-mean-square (RMS), pattern parameter, operating parameters on friction coefficient, area ratio, depth self-defined dimple were studied. Results show that coefficient will be significantly reduced during optimization effect roughness. variation laws...