The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Yishuo Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Flow characteristics of blade unit of a tridimensional Rotational Flow sieve tray under concurrent gas liquid Flow
Authorea Preprints, 2020Co-Authors: Hongkai Wang, Yishuo Zhang, Ruojin Wang, Baisong Hu, Meng Tang, Dewu Wang, Shaofeng ZhangAbstract:The Flow characteristics of the blade unit of a tridimensional Rotational Flow sieve tray was investigated experimentally in this study. First, the Flow patterns are defined under different liquid arrangement methods. They are bilateral film Flow, continuous perforated Flow, and dispersion-mixing Flow in overFlow distribution and film and jet Flow and jet and mixed Flow in spray distribution. Second, the time and frequency domain analysis of the differential pressure pulsation signal in the blade unit is carried out. The influence of perforation and mixing intensity on the Flow pattern transition is clarified. Third, the Rotational Flow ratio of the gas-liquid phase is measured. The influence of the operating conditions on the distribution of the Rotational and perforated Flow for the gas-liquid phase is investigated. Finally, a prediction model for the Rotational Flow ratio is proposed. The prediction results agree well with the experimental data.
-
cfd simulation and experimental study of dry pressure drop and gas Flow distribution of the tridimensional Rotational Flow sieve tray
Chemical Engineering Research & Design, 2017Co-Authors: Meng Tang, Shaofeng Zhang, Dewu Wang, Yishuo ZhangAbstract:Abstract A novel column internal was proposed, named tridimensional Rotational Flow sieve tray(TRST). Using CFD simulation and experimental methods, we examined the dry pressure drop and gas Flow distribution when gas Flows downward through the TRST. The results indicate that compared with other common trays, the dry pressure drop of TRST is lower (less than 70 Pa). In the TRST, there are two kinds of gas Flows: one is the Rotational Flow between the adjacent two twisted sieve blades, the other is the Flow through perforations at the sieve holes. They are coupled with each other. Subjected to diversion and restriction from the twisted sieve blades, in the upper part of the tray, the gas is at the stage of starting Rotational Flow, the velocity is lower and the static pressure is larger, both the forward and backward Flow through perforations exist; in the middle and lower part of the tray, the gas is at the stage of full developed Rotational Flow, the velocity is larger, the static pressure is lower and the Flow through perforations of gas is all in forward.
Kaige Shi - One of the best experts on this subject based on the ideXlab platform.
-
Theoretical and Experimental Study and Design Method of Blade Height of a Rotational-Flow Suction Unit in a Wall-Climbing Robot
Journal of Mechanisms and Robotics, 2020Co-Authors: Ningning Chen, Kaige ShiAbstract:Abstract A wall-climbing robot that uses a Rotational-Flow suction unit to be non-contact-absorbed onto walls can climb rough walls and overstep obstacles. In the Rotational-Flow suction unit, the air driven by the blades rotates at a high speed within a chamber, thereby creating and maintaining a negative pressure distribution. This study is focused on the modeling and design of the blade height. First, a theoretical model of the rotation Flow, containing two important parameters (i.e., blade height Hb and clearance h), was established and verified experimentally. Furthermore, the computational fluid dynamics (CFD) method was applied to illustrate the secondary Flow relative to the blades, revealing that it gives rise to a nonlinear velocity distribution. It was found that an increase in the blade height greatly improves the F–h characteristics; in addition, the relationship between the power consumption and suction force (E˙−F curve) is mainly determined by the clearance h instead of the blade height Hb. Based on these findings, we propose a design method for determining the suitable blade height. According to the characteristic load curves of the suction units (i.e., the T–ω curves) and the motor characteristics, suitable blades can be selected to match the motor operation (i.e., nominal operating state).
-
ICCMA - Theoretical Modeling and Efficiency Improvement of Electrically Activated Rotation-Flow Gripper
2019 7th International Conference on Control Mechatronics and Automation (ICCMA), 2019Co-Authors: Kaige ShiAbstract:An electrically activated rotation-Flow gripper uses rotating airFlow to generate negative pressure and suction force on a workpiece. The Rotational Flow is directly driven by a fan connected to an electrical motor, so the gripper only consumes electrical power. Because the centrifugal force generated by the rotating Flow helps prevent vacuum leakage, the gripper can handle workpieces with rough and uneven surfaces. In this study, the torque to drive the Rotational Flow in the rotating chamber and the suction force generated by the gripper are modeled, based on which the efficiency of the gripper can be obtained. The theoretical model shows efficiency could be improved by decreasing the suction force and increasing the size of the gripper. It is also found that adding a disc at the top end of the fan can improve the efficiency of the gripper by 35%. The disc could transform the Flow between the fan and the upper shell wall into a turbulent plane Couette Flow, thus reducing the driving torque by 24%. In addition, the disc isolated the insufficiently rotating Flow near the upper shell wall from the sufficiently rotating Flow below it, thereby further increasing the efficiency by increasing the suction force. The theoretical model and the efficiency improvement are verified by experiments.
Meng Tang - One of the best experts on this subject based on the ideXlab platform.
-
Flow characteristics of blade unit of a tridimensional Rotational Flow sieve tray under concurrent gas liquid Flow
Authorea Preprints, 2020Co-Authors: Hongkai Wang, Yishuo Zhang, Ruojin Wang, Baisong Hu, Meng Tang, Dewu Wang, Shaofeng ZhangAbstract:The Flow characteristics of the blade unit of a tridimensional Rotational Flow sieve tray was investigated experimentally in this study. First, the Flow patterns are defined under different liquid arrangement methods. They are bilateral film Flow, continuous perforated Flow, and dispersion-mixing Flow in overFlow distribution and film and jet Flow and jet and mixed Flow in spray distribution. Second, the time and frequency domain analysis of the differential pressure pulsation signal in the blade unit is carried out. The influence of perforation and mixing intensity on the Flow pattern transition is clarified. Third, the Rotational Flow ratio of the gas-liquid phase is measured. The influence of the operating conditions on the distribution of the Rotational and perforated Flow for the gas-liquid phase is investigated. Finally, a prediction model for the Rotational Flow ratio is proposed. The prediction results agree well with the experimental data.
-
cfd simulation and experimental study of dry pressure drop and gas Flow distribution of the tridimensional Rotational Flow sieve tray
Chemical Engineering Research & Design, 2017Co-Authors: Meng Tang, Shaofeng Zhang, Dewu Wang, Yishuo ZhangAbstract:Abstract A novel column internal was proposed, named tridimensional Rotational Flow sieve tray(TRST). Using CFD simulation and experimental methods, we examined the dry pressure drop and gas Flow distribution when gas Flows downward through the TRST. The results indicate that compared with other common trays, the dry pressure drop of TRST is lower (less than 70 Pa). In the TRST, there are two kinds of gas Flows: one is the Rotational Flow between the adjacent two twisted sieve blades, the other is the Flow through perforations at the sieve holes. They are coupled with each other. Subjected to diversion and restriction from the twisted sieve blades, in the upper part of the tray, the gas is at the stage of starting Rotational Flow, the velocity is lower and the static pressure is larger, both the forward and backward Flow through perforations exist; in the middle and lower part of the tray, the gas is at the stage of full developed Rotational Flow, the velocity is larger, the static pressure is lower and the Flow through perforations of gas is all in forward.
Qiang Zhou - One of the best experts on this subject based on the ideXlab platform.
-
Experimental investigation on climbing robot using rotation-Flow adsorption unit
Robotics and Autonomous Systems, 2018Co-Authors: Qiang ZhouAbstract:Abstract Traditional climbing robots that use vacuum suckers have some technical problems, e.g., inability to climb coarse walls, frictional resistance and abrasion of suckers, and poor obstacle-surmounting ability. In this study, a new negative pressure adsorption mechanism is applied to the design of a climbing robot. This mechanism generates and maintains negative pressure and adsorption force by using the air’s Rotational inertia effect; therefore, the structure incorporating this mechanism is called the Rotational-Flow adsorption unit. The most important characteristic of the adsorption unit is that it can function without being in contact with the wall, which fundamentally solves these technical problems associated with traditional climbing robots. In this study, we designed a square-shaped Rotational-Flow adsorption unit to improve the robot’s load ability (18% increase in the adsorption force) and designed a soft skirt structure to improve the robot’s obstacle-surmounting ability (e.g., passing through 15-mm-high bulges). Finally, we fabricated a prototype of the climbing robot and tested it on several actual walls (extremely coarse wall, wall containing deep groove, and wall containing large bulges). The test results show that our prototype robot can move stably on coarse walls and can pass over large grooves and bulges easily.
-
design of wall climbing robot using electrically activated Rotational Flow adsorption unit
Intelligent Robots and Systems, 2016Co-Authors: Qiang ZhouAbstract:Traditional climbing robots that use vacuum suckers have some technical problems, e.g., inability to climb coarse walls, frictional resistance and abrasion of suckers, and poor obstacle-surmounting ability. In this study, a new negative pressure adsorption mechanism is applied to the design of a climbing robot. This mechanism generates and maintains negative pressure and adsorption force by using the air's Rotational inertia effect; therefore, the structure incorporating this mechanism is called the electrically activated Rotational-Flow adsorption unit. The most important characteristic of the adsorption unit is that it can function without being in contact with the wall, which fundamentally solves these technical problems associated with traditional climbing robots. In this study, we designed a square-shaped Rotational-Flow adsorption unit to improve the robot's load ability (18% increase in the adsorption force) and designed a soft skirt structure to improve the robot's obstacle-surmounting ability. Finally, we fabricated a prototype of the climbing robot and tested it on a actual wall (extremely coarse wall, wall containing a large groove). The test results show that our prototype robot can move stably on extremely coarse walls and can pass over large grooves easily.
-
IROS - Design of wall-climbing robot using electrically activated Rotational-Flow adsorption unit
2016 IEEE RSJ International Conference on Intelligent Robots and Systems (IROS), 2016Co-Authors: Qiang ZhouAbstract:Traditional climbing robots that use vacuum suckers have some technical problems, e.g., inability to climb coarse walls, frictional resistance and abrasion of suckers, and poor obstacle-surmounting ability. In this study, a new negative pressure adsorption mechanism is applied to the design of a climbing robot. This mechanism generates and maintains negative pressure and adsorption force by using the air's Rotational inertia effect; therefore, the structure incorporating this mechanism is called the electrically activated Rotational-Flow adsorption unit. The most important characteristic of the adsorption unit is that it can function without being in contact with the wall, which fundamentally solves these technical problems associated with traditional climbing robots. In this study, we designed a square-shaped Rotational-Flow adsorption unit to improve the robot's load ability (18% increase in the adsorption force) and designed a soft skirt structure to improve the robot's obstacle-surmounting ability. Finally, we fabricated a prototype of the climbing robot and tested it on a actual wall (extremely coarse wall, wall containing a large groove). The test results show that our prototype robot can move stably on extremely coarse walls and can pass over large grooves easily.
Shaofeng Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Flow characteristics of blade unit of a tridimensional Rotational Flow sieve tray under concurrent gas liquid Flow
Authorea Preprints, 2020Co-Authors: Hongkai Wang, Yishuo Zhang, Ruojin Wang, Baisong Hu, Meng Tang, Dewu Wang, Shaofeng ZhangAbstract:The Flow characteristics of the blade unit of a tridimensional Rotational Flow sieve tray was investigated experimentally in this study. First, the Flow patterns are defined under different liquid arrangement methods. They are bilateral film Flow, continuous perforated Flow, and dispersion-mixing Flow in overFlow distribution and film and jet Flow and jet and mixed Flow in spray distribution. Second, the time and frequency domain analysis of the differential pressure pulsation signal in the blade unit is carried out. The influence of perforation and mixing intensity on the Flow pattern transition is clarified. Third, the Rotational Flow ratio of the gas-liquid phase is measured. The influence of the operating conditions on the distribution of the Rotational and perforated Flow for the gas-liquid phase is investigated. Finally, a prediction model for the Rotational Flow ratio is proposed. The prediction results agree well with the experimental data.
-
cfd simulation and experimental study of dry pressure drop and gas Flow distribution of the tridimensional Rotational Flow sieve tray
Chemical Engineering Research & Design, 2017Co-Authors: Meng Tang, Shaofeng Zhang, Dewu Wang, Yishuo ZhangAbstract:Abstract A novel column internal was proposed, named tridimensional Rotational Flow sieve tray(TRST). Using CFD simulation and experimental methods, we examined the dry pressure drop and gas Flow distribution when gas Flows downward through the TRST. The results indicate that compared with other common trays, the dry pressure drop of TRST is lower (less than 70 Pa). In the TRST, there are two kinds of gas Flows: one is the Rotational Flow between the adjacent two twisted sieve blades, the other is the Flow through perforations at the sieve holes. They are coupled with each other. Subjected to diversion and restriction from the twisted sieve blades, in the upper part of the tray, the gas is at the stage of starting Rotational Flow, the velocity is lower and the static pressure is larger, both the forward and backward Flow through perforations exist; in the middle and lower part of the tray, the gas is at the stage of full developed Rotational Flow, the velocity is larger, the static pressure is lower and the Flow through perforations of gas is all in forward.
