Li Chen

A major issue for human growth is the energy crisis. In the current study, circular pipes are considered an energy-efficient technology viable in all seasons. It uses non-constant soil temperature and water flow in coldest regions. This model reports the thermal performance of pipes with different results in hot and cold climates. To degree thermal performance, pipe version changed into advanced and simulated with ANSYS 18.1 Fluid Flow (Fluent). Data was collected from two modelled summer and winter seasons. Continuity, momentum, and energy equation have been used for the simulation. Comparison analysis is also being carried out about the obtained results with previously published articles. The effects of summer and winter temperature and speed on performance were also evaluated. Further, the graphical interpretation is also carried for velocity and pressure distribution. The study highlights a drastic drop in temperature and velocity near the inlet and outlet region while Pressure is inversely proportional to velocity in these regions. It is also obtained from the simulation that the temperature pressure and velocity remain uniform in the fully develop region.

With the growing emphasis on environmental protection, the engineering construction industry is facing new demands. The widespread electrification of construction machinery has emerged as an inevitable trend. To align with this trend, this paper conducts research on the model predictive control algorithm (MPC) applied to permanent magnet synchronous motors (PMSM). The MPC algorithm primarily consists of the motor’s mathematical model and the cost function. This study focuses on analyzing the weight factor within the cost function. The spectrum of weight factor combinations concerning the dq-axis current is formulated across a broad range of intervals. The algorithm’s performance is assessed under various weight factors using experimental data from three-phase current operation, motor torque, rotational speed, and other parameters. Ultimately, a novel evaluation function is proposed in this study to quantitatively assess the algorithm’s performance across various combinations. The process involves identifying the optimal combination of weight factors for the cost function. This effort contributes significantly to establishing a robust groundwork for the general electrification of construction machinery.

Due to its vast industrial applications and biological context, the investigation of the inconsistent heat and mass transfer that drives the flow of squeezing viscous nanofluids between two plates is a fascinating topic. In this study, we investigated the heat transfer analysis of unsteady viscous nanofluid between two parallel plates. The partial differential equations illustrating the flow model are converted to nonlinear ordinary differential equations by suggesting similarity transformations. The resulting dimensionless and nonlinear ODEs of temperature functions and velocity are solved using the well know numerical technique shooting method by transforming the problem into initial value problem from boundary value problem. The results found are consistent with this numerical solution. Graphically explore the impacts of different parameters on temperature profiles and velocity. The results are compared with the results solved by HPM. The results concurred with this numerical solution. These findings are considered much be useful in the application of polymer processing, power transmission, compression, temporary loading of mechanical parts, food processing, cooling water, gravity machinery, modeling of plastic transport in vivo, chemical processing instruments, and demolition due to freezing.

The calculus in the absence of limits is known as quantum calculus. With a difference operator, it substitutes the classical derivative, which permits dealing with sets of functions that are non-differentiations. The theory of integral inequality in quantum calculus is a field of mathematics that has been gaining considerable attention recently. Despite the fact of its application in discrete calculus, it can be applied in fractional calculus as well. In this paper, some new Anderson type q-integral and h-integral inequalities are given using a Feng Qi integral inequality in quantum calculus. These findings are highly beneficial for basic frontier theories, and the techniques offered by technology are extremely useful for those who can stimulate research interest in exploring mathematical applications. Due to the interesting properties in the field of mathematics, integral inequalities have a tied correlation with symmetric convex and convex functions. There exist strong correlations and expansive properties between the different fields of convexity and symmetric function, including probability theory, convex functions, and the geometry of convex functions on convex sets. The main advantage of these essential inequalities is that they can be converted into time-scale calculus. This kind of inevitable inequality can be very helpful in various fields where coordination plays an important role.

This paper deals with the MHD peristaltic flow of Williamson fluids through a porous medium between two joint cylinders. The fluid flow was considered to be that of a non-Newtonian fluid, i.e., a Williamson fluid. The inner tube was uniform, while the flexible outer tube had a Sine wave moving down its wall. The analytical solutions for velocity and temperature were obtained as functions (Bessell functions of the first and second types). The solution for velocity profile, temperature, and concentration distribution were obtained as functions of the physical parameters of the problem (Darcy number, magnetic parameter, Grasoff thermal number, Reynolds number, Prantl number, and Schmidt number) along with other physical parameters. The effect of the physical parameters was discussed graphically. A comparison with previously published graphical results was also carried out. The ambition of the present paper is to contribute to practical applications in geographical and physiological fluid dynamics, such as on sandstone, in the human lungs, on beach sand, on limestone, and in the bile duct. This study is based on theoretical research and can be helpful in the fields of fluid mechanics and mathematics.

Various industrial operations involve frequent heating and cooling of electrical systems. In such circumstances, the development of relevant thermal devices is of extreme importance. During the development of thermal devices, the second law of thermodynamics plays an important role by means of entropy generation. Entropy generation should be reduced significantly for the efficient performance of the devices. The current paper reports an analytical study on micropolar fluid with entropy generation over a stretching surface. The influence of various physical parameters on velocity profile, microrotation profile, and temperature profile is investigated graphically. The impact of thermal radiation, porous medium, magnetic field, and viscous dissipation are also analyzed. Moreover, entropy generation and Bejan number are also illustrated graphically. Furthermore, the governing equations are solved by using HAM and code in MATHEMATICA software. It is concluded from this study that velocity and micro-rotation profile are reduced for higher values of magnetic and vortex viscosity parameter, respectively. For larger values of Eckert number and thermal radiation parameters, Bejan number and entropy generation are increased, respectively. These findings are useful in petroleum industries and engineering designs.

A combined immersed boundary–lattice Boltzmann approach is used to simulate the dynamics of the fluid–structure interaction of a hollow sealing strip under the action of pressure difference. Firstly, the multiple relaxation times LBM model, hyper-elastic material model and immersed boundary method were deduced. According to the strain characteristics of hyper-elastic materials and the specific situation of friction between the elastic boundary and solid boundary, the internal force and the external force on the immersed boundary were discussed and deduced, respectively. Then, a 2D calculation model of the actual hollow sealing strip system was established, during which technical problems such as the equivalent wall thickness of the sealing strip and the correction of the stiffness of the contact corner were solved. The reliability of the model was verified by comparing results of FEM simulation of quasi-static deformation. Following this, the simulation results of three typical cases of sealing strips were presented. The results show that when the sealing strip fails, there will be a strong coupling phenomenon between the flow field and the sealing strip, resulting in the oscillation of the flow field and the sealing strip at the same frequency.

This paper gives the current regulator design for a dual Y shift 30 degrees permanent magnet synchronous motor (DT_PMSM) based on the vector space decomposition (VSD). Current regulator design in α-β subspace is insufficient and designing additional controllers in x-y subspace is necessary to eliminate the harmonic currents due to the nonlinear characteristics of the inverter. A sliding mode controller based on an internal model is proposed in α-β subspace, which is robust to the parameter uncertainties and disturbances in current control loops. In order to eliminate the harmonic currents in x-y subspace, a resonant controller is employed based on a new synchronous rotating matrix. Three-phase decomposition space vector pulse width modulation (SVPWM) technique is illustrated for the purpose of synthesizing the voltage vectors in both subspaces simultaneously. The feasibility and efficiency of the suggested current regulator design are validated by a set of experimental results.