Advances in Mechanical Engineering, Volume 16, Issue 5, May 2024. The energy harvester based on the piezoelectric effect can convert the vibration energy in the environment into electricity to power the network nodes. In order to broaden the effective frequency bandwidth of the piezoelectric energy harvester and reduce the resonant frequency of the system, a liquid slosh-type piezoelectric energy harvester is proposed in this paper. Based on the theory of the piezoelectric effect, the mechanical model and electromechanical coupling model of the piezoelectric energy harvester were established ..read more

Advances in Mechanical Engineering, Volume 16, Issue 4, April 2024. Machining-induced residual stress (MIRS) in thin-walled components affects their machining accuracy, especially for large-size thin-walled components. This study focuses on the bodies of marine diesel engines, exploring the distribution of MIRS and distortion caused by the gravity-coupled machining residual stress during the boring process of the main bearing hole. The research obtained the distribution of MIRS and the machining distortion based on the finite element method and the mapping method. It examined the influence rul ..read more

Advances in Mechanical Engineering, Volume 16, Issue 4, April 2024. The master cylinder of most pump trucks is equipped with a waterproof valve, whose purpose is to prevent water from the tank from entering the master cylinder. Once waterproof valve fails to failure, the waterproof valve at the main cylinder can only be supported by a BS seal (this seal is very easy to fail), which results in oil emulsification and pollution of the hydraulic system. Therefore, a fault diagnosis method combining a multi-sensor high-dimensional time-domain feature expansion map (MHTFEM) with an attentional convo ..read more

Advances in Mechanical Engineering, Volume 16, Issue 4, April 2024. The slip flow phenomenon caused by the gas floating seal in ultra-thin gas films and high-altitude rarefied gas environments occurs frequently. This study represents the first attempt to calculate the gas film floating force by considering the coupling relationship among the slip flow effect, the surface micro-grooves, and the eccentricity using a high-precision eight-node finite difference method based on the linearized Boltzmann equation for a spiral-grooved cylindrical gas seal. Furthermore, the influence of slip flow on th ..read more

Advances in Mechanical Engineering, Volume 16, Issue 4, April 2024. To investigate the effect of various factors on bearing stress response, Huber-Hencky-von Mises stress serves as a bridge, the equivalent interrelation between radial loading, axial loading, and temperature of bearing is studied using finite element method (FEM). Symbolic regression (SR) algorithm is employed to analyze simulation results, establishing a functional expression between independent and dependent variables by optimizing combinations of variables, constants, and functional forms. The results showed that within the ..read more

Advances in Mechanical Engineering, Volume 16, Issue 4, April 2024. Bearing faults in gearbox systems pose critical challenges to industrial operations, needing advanced diagnostic techniques for timely and accurate identification. In this paper, we propose a new hybrid method for automated classification and identification of defective bearings in gearbox systems with identical rotating frequencies. The method successfully segmented the signals and captured specific frequency components for deeper analysis employing three distinct signal processing approaches, ensemble empirical mode decompos ..read more

Advances in Mechanical Engineering, Volume 16, Issue 4, April 2024. This study explores heat transfer in a system involving Jeffery fluid of MHD flow and a porous stretching sheet. The mathematical representation of this system is initially described using a partial differential equation (PDE), which is then converted into an ordinary differential equation (ODE) through numerical techniques such as Lie similarity and transformation methods, along with the shooting approach. The results indicate that altering the variables of Jeffery fluid, heat source, porosity on a stretching sheet, and the p ..read more

Advances in Mechanical Engineering, Volume 16, Issue 4, April 2024. The function of the turbo-pump shaft within the liquid rocket engine is rendered exceedingly complex due to the operation in an environment characterized by drastically low temperatures, elevated velocities, and high pressures. Given these operational conditions, it is highly plausible that a two-phase flow might form within the liquid film located on the terminal face of the mechanical seal. This liquid-vapor mixture significantly modifies the fluid lubrication pattern across the end faces and poses consequential implications ..read more

Advances in Mechanical Engineering, Volume 16, Issue 4, April 2024. This study investigates flow of non-Newtonian fluid containing nano particles and gyrotactic micro-organisms on stretching surface considering magnetic factor and thermal radiations. Cattaneo-Christov model is employed to analyze flow characteristics. The governing Partial Differential Equations (PDEs) along with associated boundary conditions describing the model are converted into Ordinary Differential Equations (ODEs) by suitable transformations. Homotopy Analysis Method (HAM), a semi-analytic solution technique is employed ..read more

Advances in Mechanical Engineering, Volume 16, Issue 4, April 2024. Gaussian road profile is widely used to study vehicle response and fatigue damage potential, while field measured road profile often is non-Gaussian. In this paper, a new amplitude modulation method which has full control of cutoff frequency (denoted as Wcut) and amplitude of the amplitude modulation signal is firstly presented to synthesize non-Gaussian road profile with different kurtosis. The forced response of a quarter vehicle under non-Gaussian road profile excitation is then calculated using the ramp invariant digital f ..read more