The raceway is the energy source and core reaction region in blast furnace (BF). This study creates a polyhedral particle based on BF charge. effects of shape, tuyere velocity, deadman resistance microstructure mechanical properties are analyzed discrete element method‐computational fluid dynamics method. results show that with velocity 200 m s −1 , pressure gradient drag forces particles 60.94% 70.06% higher than those spherical particles, height depth 26.76% 57.14% respectively. size...

Abstract The aerodynamic layout of a bristle wing has an influence on its flight performance. performance at low Reynolds number seems to be related diffusion angle compared with that vehicle high number. We designed three different angles for numerical simulation under steady-state incoming flow fixed attack and observed the changes drag shear force acting wings angles. found effect coefficient decreases increase number, which is fact leakage rate exhibits very characteristics numbers. This

Target direction-of-arrival (DOA) estimation is often difficult in the presence of strong interference—especially when target DOA very close to interference DOA—since signal can mask weak and make hard. To address this problem, an efficient sparse method for proposed paper, which effect on significantly reduced. An on-grid version grid evolution technique then developed nonuniformly refine grid, thereby reducing computational complexity while retaining reasonable accuracy. Numerical...

In mechanized rice harvesting, the performance of cleaning device is one important factors that affect overall efficiency combine-harvester. To study influence different parameters on efficiency, airflow velocity and inclination angle effect was analyzed. Both simulation experimental results prove increase will reduce impurity rate entrainment loss rate. The addition a vibrating sieve to reduces trash rice, but entrained increases accordingly. After tilting surface by 10°, reduction in both...

A two-dimensional cylindrical shell (2DCS) structure with radial and circumferential periodicities is proposed in this paper. The band gap characteristics of wave propagating radically from the inner circle are investigated numerically. According to calculation discussion transmission behavior, found show distinct attenuation certain frequency region, i.e. gap. internal mechanism then Bragg scattering effect illustrated. Furthermore, detailed behaviors within studied, especially for peaks....

The life of the hearth is main limiting link campaign a blast furnace. As equipment for holding molten iron in furnace, high-temperature direct contact with refractory, which makes refractory have larger temperature increase. If gradient inside large, it generates large thermal stress and causes to crack. Blast furnace gas intrude into gap, directly melting erosion other chemical carbon bricks. It aggravates degree seriously affects production Therefore, often occurs different types severe...

In recent years, more and attention has been paid to research on variable geometry turbine engines with the increasing requirement of engine performance. Variable technology can significantly improve operating performance aero engines. Adjusting working angle guide vane change thermodynamic cycle operation, so that respond different conditions. turbines work in harsh environments. Therefore, design needs consider effect thermal deformations mechanism operational stability. There are few...

In order to study the movement characteristics and separation mechanism of rice its impurities under action airflow, lower impurity rate in cleaning operation process, were modeled based on "overlapping multi-sphere clump method", DEM-CFD coupling method was used simulate process different airflow velocity inclined angle, combined with aerodynamics, motion state behavior flow field. The results showed that horizontal conditions, average lowest when 9 m/s. When remains unchanged angle set at...

Based on the effective-medium theory, propagation of a shear horizontal (SH) wave in joined half-spaces composed elastic metamaterials (EMMs) is investigated. From dispersion relations, effects negative parameters properties SH traveling near interface are analyzed detail. It found that can always appear and travel along under specific effective-parameter combinations no matter whether effective transverse velocity imaginary or real. This significantly different from classical case (joined...

The blast furnace hearth is the key position to determine life of furnace. To ensure safety hearth, when serious local depression erosion occurs in lining, necessary protection measures are taken prevent from continuing expand. At present, and strength mostly selected according engineering experience, lacking feasible theoretical methods predict effect protection. In this paper, a three-dimensional numerical model thermofluid-solid coupling with mushroom-type was established. Taking...

In the process of horizontal well construction, working environment in is very complicated. It difficult to determine actual deformation and force coiled tubing wellbore from load change at wellhead along. addition, wrapped around reel entering through injection head may cause an initial residual bending. this paper, mathematical model under axial during buckling established, analytical solution with time term derived by reasonable simplification model. The effect bending on post-sinusoidal...

Abstract This study developed a gravel soil granular bed model using the discrete element method, elaborating on core barrel drilling process by integrating bond-breaking and particle flow patterns. A quantitative description of is achieved defining efficiency. The results indicate that force particles near drill tooth greatest, this increases with feed rate, which enhances efficiency exacerbates wear guide bars. An increase in rotational speed raises boundary region, leading to deeper bar;...

Array design is the primary consideration for array signal processing, and sparse an important challenging task. In underwater acoustic environments, vector hydrophone contains more information than scalar array, but there are few articles focused on of array. The difference between that each has three or four channels. When designing a these channels need to be optimized at same time ensure sparsity elements' number. To solve this problem, paper introduced compressed sensing (CS) theory...

More and more attention has been paid to research on variable geometry turbine engines with the increasing improvement of performance requirements for military turbines. Due fixed working angle inlet guide vane, a conventional is optimal only turbines near design point. To match aircraft's starting, climbing, cruising, deceleration, landing other states, it necessary change speed. This will not reduce but also increase fuel loss. The perfect solution this problem. It speed turbine, rotating...