Recent Patent on a Tree-type Cylindrical-shaped Nanoporous Filtering Membrane

2019 ◽  
Vol 13 (4) ◽  
pp. 308-311
Author(s):  
Yongbin Zhang
Keyword(s):  
Flow Resistance ◽  
Design Method ◽  
Membrane Surface ◽  
Low Flow ◽  
High Flux ◽  
Liquid Separation ◽  
Operational Parameter ◽  
Good Filtration ◽  
Parameter Values ◽  
Tree Type

Background: Nanoporous filtering membranes can be used for super purification including a liquid-liquid separation. It is the aim of engineers to design these membranes with good filtration capabilities, high fluxes and satisfying mechanical strengths. Realistic membranes need to have a balance among these performances to achieve satisfactory overall performances. Objective: The study aims to show a tree-type cylindrical-shaped nanoporous filtering membrane with good characteristics. Methods: According to the principle of the nanotube tree for transportation presented previously, here the design method of a tree-type cylindrical shaped nanoporous filtering membrane is presented and the flow resistances of this membrane have been calculated for varying operational parameter values. Results: It is shown that the invented membrane possesses nanoscale filtration pores and larger flow-resistance-reducing pores. These pores are densely evenly distributed on the membrane surface. The membrane practically has a low flow resistance and thus a high flux if its thickness is as small as possible. It can also be used for a liquid-liquid separation if the mixed liquids have largely different interactions with the pore walls of the membrane. Conclusion: By an appropriate design, the invented membrane has a good overall performance including the capabilities of super purification or a liquid-liquid separation, the high flux and a satisfactory mechanical strength.

Optimized Tree-Type Cylindrical-Shaped Nanoporous Filtering Membranes with 3 or 5 Branch Pores in Each Pore Tree

2019 ◽  
Vol 15 (6) ◽  
pp. 647-653
Author(s):  
Yongbin Zhang
Keyword(s):  
Flow Resistance ◽  
Design Method ◽  
Pore Wall ◽  
Optimum Operating ◽  
Liquid Particle ◽  
Liquid Separation ◽  
Optimum Operating Condition ◽  
Liquid Separations ◽  
Flow Resistances ◽  
Tree Type

Background: It is necessary to investigate the performances of the optimized tree-type cylindrical-shaped nanoporous filtering membranes with 3 or 5 branch pores in each pore tree. Objective: To explore the design method for and the performances of the liquid-particle and liquidliquid separations of the optimized tree-type cylindrical-shaped nanoporous filtering membranes with 3 or 5 branch pores in each pore tree. Methods: The analysis was made for the flow resistance of the studied membrane based on the nanoscale flow equation. The optimum ratios of the radius of the trunk pore to the radius of the branch pore were typically calculated for yielding the lowest flow resistance of this membrane. The capability of the liquid-liquid separation of this membrane was investigated by exploring the flow resistances of this membrane for different liquids. Results: The optimum ratios of the radius of the trunk pore to the radius of the branch pore were typically calculated for the maximum fluxes of these membranes for different passing liquid-pore wall interactions. They can be used for the design of the studied membranes for liquid-particle or liquid-liquid separations. The flow resistances of the studied membranes in the optimum condition for different liquids were also calculated, and the capability of the liquid-liquid separation of the membranes is evidenced. Conclusion: The obtained results can be used for the design of the studied membranes for achieving their optimum operating condition, by taking the ratio of the radius of the trunk pore to the radius of the branch pore as optimum. The studied membranes also have good capabilities of liquid-liquid separations if the mixed liquids have greatly different interactions with the pore wall and the radius of the branch pore is below 3nm or less.

scholarly journals Multistage Digital-to-Analogue Chip Based on a Weighted Flow Resistance Network for Soft Actuators

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1016
Author(s):  
Zhou Zhou ◽  
Manman Xu ◽  
Chenlin Zhu ◽  
Gonghan He ◽  
Kunpeng Zhang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Microfluidic Chip ◽  
Flow Resistance ◽  
Design Method ◽  
Control Unit ◽  
Digital Signal ◽  
Technical Problems ◽  
Pressure Signal ◽  
Resistance Network ◽  
Flow Adjustment

A control chip with a multistage flow-rate regulation function based on the correlation between the flow resistance and flow rate has been developed in this article. Compared with the traditional proportional solenoid valve, this kind of flow valve based on microfluidic technology has the characteristics of being light-weight and having no electric drive. It solves such technical problems as how the current digital microfluidic chip can only adjust the flow switch, and the adjustment of the flow rate is difficult. To linearize the output signal, we propose a design method of weighted resistance. The output flow is controlled by a 4-bit binary pressure signal. According to the binary value of the 4-bit pressure signal at the input, the output can achieve 16-stage flow adjustment. Furthermore, we integrate the three-dimensional flow resistance network, multilayer structure microvalve, and parallel fluid network into a single chip by using 3D printing to obtain a modular flow control unit. This structure enables the microflow control signal to be converted from a digital signal to an analogue signal (DA conversion), and is suitable for microflow driving components, such as in microfluidic chip sampling systems and proportional mixing systems. In the future, we expect this device to even be used in the automatic control system of a miniature pneumatic soft actuator.

Kinematic Multi-Objective Optimization of Circular-Toothed Gerotor Pumps by Genetic Algorithm

2017 ◽  
Author(s):  
Andrew J. Robison ◽  
Andrea Vacca
Keyword(s):  
Genetic Algorithm ◽  
Design Method ◽  
Third Party ◽  
Low Flow ◽  
Objective Functions ◽  
Multi Objective Optimization ◽  
Nsga Ii ◽  
Generation Algorithm ◽  
Multi Objective ◽  
Pareto Curve

A gerotor gear generation algorithm has been developed that evaluates key performance objective functions to be minimized or maximized, and then an optimization algorithm is applied to determine the best design. Because of their popularity, circular-toothed gerotors are the focus of this study, and future work can extend this procedure to other gear forms. Parametric equations defining the circular-toothed gear set have been derived and implemented. Two objective functions were used in this kinematic optimization: maximize the ratio of displacement to pump radius, which is a measure of compactness, and minimize the kinematic flow ripple, which can have a negative effect on system dynamics and could be a major source of noise. Designs were constrained to ensure drivability, so the need for additional synchronization gearing is eliminated. The NSGA-II genetic algorithm was then applied to the gear generation algorithm in modeFRONTIER, a commercial software that integrates multi-objective optimization with third-party engineering software. A clear Pareto front was identified, and a multi-criteria decision-making genetic algorithm was used to select three optimal designs with varying priorities of compactness vs low flow variation. In addition, three pumps used in industry were scaled and evaluated with the gear generation algorithm for comparison. The scaled industry pumps were all close to the Pareto curve, but the optimized designs offer a slight kinematic advantage, which demonstrates the usefulness of the proposed gerotor design method.

scholarly journals Temperature and Velocity Effects on Mass and Momentum Transport in Spacer-Filled Channels for Reverse Electrodialysis: A Numerical Study

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2028 ◽  
Author(s):  
Zohreh Jalili ◽  
Jon Pharoah ◽  
Odne Stokke Burheim ◽  
Kristian Einarsrud
Keyword(s):  
Mass Transfer ◽  
Pressure Drop ◽  
Concentration Polarization ◽  
Numerical Study ◽  
Membrane Surface ◽  
Lower Pressure ◽  
Low Flow ◽  
Fluid Temperature ◽  
Reverse Electrodialysis ◽  
Flow Velocities

Concentration polarization is one of the main challenges of membrane-based processes such as power generation by reverse electrodialysis. Spacers in the compartments can enhance mass transfer by reducing concentration polarization. Active spacers increase the available membrane surface area, thus avoiding the shadow effect introduced by inactive spacers. Optimizing the spacer-filled channels is crucial for improving mass transfer while maintaining reasonable pressure losses. The main objective of this work was to develop a numerical model based upon the Navier–Stokes and Nernst–Planck equations in OpenFOAM, for detailed investigation of mass transfer efficiency and pressure drop. The model is utilized in different spacer-filled geometries for varying Reynolds numbers, spacer conductivity and fluid temperature. Triangular corrugations are found to be the optimum geometry, particularly at low flow velocities. Cylindrical corrugations are better at high flow velocities due to lower pressure drop. Enhanced mass transfer and lower pressure drop by elevating temperature is demonstrated.

scholarly journals Design of Vegetable Pot Seedling Pick-up Mechanism with Planetary Gear Train

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Zhipeng Tong ◽  
Gaohong Yu ◽  
Xiong Zhao ◽  
Pengfei Liu ◽  
Bingliang Ye
Keyword(s):  
Design Method ◽  
Planetary Gear ◽  
Gear Train ◽  
Dimensional Synthesis ◽  
Planetary Gear Train ◽  
Key Points ◽  
Physical Prototype ◽  
Noncircular Gears ◽  
Pitch Curve ◽  
Parameter Values

Abstract It has been challenging to design seedling pick-up mechanism based on given key points and trajectories, because it involves dimensional synthesis and rod length optimization. In this paper, the dimensional synthesis of seedling pick-up mechanism with planetary gear train was studied based on the data of given key points and the trajectory of the endpoint of seedling pick-up mechanism. Given the positions and orientations requirements of the five key points, the study first conducted a dimensional synthesis of the linkage size and center of rotation. The next steps were to select a reasonable solution and optimize the data values based on the ideal seedling trajectory. The link motion was driven by the planetary gear train of the two-stage gear. Four pitch curves of noncircular gears were obtained by calculating and distributing the transmission ratio according to the data. For the pitch curve with two convex points, the tooth profile design method of incomplete noncircular gear was applied. The seedling pick-up mechanism was tested by a virtual prototype and a physical prototype designed with the obtained parameter values. The results were consistent with the theoretical design requirements, confirming that the mechanism meets the expected requirements for picking seedlings up. This paper presents a new design method of vegetable pot seedling pick-up mechanism for an automatic vegetable transplanter.

Optimal Design Method of Fins in Automotive Oil Cooler Based on the Thermal-Hydraulic Performances

2012 ◽  
Vol 490-495 ◽  
pp. 2381-2385
Author(s):  
Bao Lan Xiao ◽  
Wei Ming Wu ◽  
Xiao Li Yu ◽  
Guo Dong Lu
Keyword(s):  
Heat Transfer ◽  
Neural Networks ◽  
Optimal Design ◽  
Heat Exchangers ◽  
Flow Resistance ◽  
Design Method ◽  
Normal Operation ◽  
Oil Cooler ◽  
Optimal Design Method ◽  
Simulation Results

The excellent thermal-hydraulic performances of oil cooler are the strong guaranty for automotives’ normal operation. In this study, the thermal-hydraulic performances of compact oil cooler units with different fin size parameters are numerical simulated. According to simulation results, combined with neural networks method, the optimal fin size parameters are determined. Based on this, the effects of different fin arrange layouts on performances are also studied, and optimal layouts for different requirements for flow resistance and heat transfer performances are put forward. This optimal design method can play a guidance role for the designer and manufacturer of heat exchangers.

Optimization of the lubrication system in a turbocharged engine

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940011
Author(s):  
Cho-Yu Lee ◽  
Dani Joseph Veera ◽  
Huan-Yuan Chen ◽  
Jui-Hung Chang ◽  
Kao-Ruei Hung
Keyword(s):  
Pressure Drop ◽  
Flow Resistance ◽  
Engine Speed ◽  
System Optimization ◽  
Low Flow ◽  
Lubrication System ◽  
Mechanical Loss ◽  
Oil Pump ◽  
Oil Cooler ◽  
Base Engine

Lubricating the engine reciprocating components effectively against various engine speeds is significant for a proper lubrication system. This paper presents the lubrication system optimization of a twin cylinder 700 c.c. turbocharged engine. A couple of modifications were tested including correction of ducts misalignment, consistence diameter of ducts and replacement of a low flow resistance oil cooler. Compared to the base engine, experimental results prove that differential pressure (DP) between the oil pump and main oil gallery has been decreased to a minimum 19% and maximum 54% at engine speed between 2000 and 7000 rpm. The lower the pressure drop, the lower the flow resistance. Thus, mechanical loss has also been improved.

scholarly journals A New Method for Impeller Inlet Design of Supercritical CO2 Centrifugal Compressors in Brayton Cycles

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5049
Author(s):  
Xiaojian Li ◽  
Yijia Zhao ◽  
Huadong Yao ◽  
Ming Zhao ◽  
Zhengxian Liu
Keyword(s):  
Design Method ◽  
Operating Conditions ◽  
Low Flow ◽  
Working Fluid ◽  
Centrifugal Compressors ◽  
Flow Angle ◽  
Real Gas ◽  
Total Condition ◽  
Swallowing Capacity ◽  
Cycle Efficiency

Supercritical Carbon Dioxide (SCO2) is considered as a potential working fluid in next generation power and energy systems. The SCO2 Brayton cycle is advantaged with higher cycle efficiency, smaller compression work, and more compact layout, as compared with traditional cycles. When the inlet total condition of the compressor approaches the critical point of the working fluid, the cycle efficiency is further enhanced. However, the flow acceleration near the impeller inducer causes the fluid to enter two-phase region, which may lead to additional aerodynamic losses and flow instability. In this study, a new impeller inlet design method is proposed to achieve a better balance among the cycle efficiency, compressor compactness, and inducer condensation. This approach couples a concept of the maximum swallowing capacity of real gas and a new principle for condensation design. Firstly, the mass flow function of real gas centrifugal compressors is analytically expressed by non-dimensional parameters. An optimal inlet flow angle is derived to achieve the maximum swallowing capacity under a certain inlet relative Mach number, which leads to the minimum energy loss and a more compact geometry for the compressor. Secondly, a new condensation design principle is developed by proposing a novel concept of the two-zone inlet total condition for SCO2 compressors. In this new principle, the acceptable acceleration margin (AAM) is derived as a criterion to limit the impeller inlet condensation. The present inlet design method is validated in the design and simulation of a low-flow-coefficient compressor stage based on the real gas model. The mechanisms of flow accelerations in the impeller inducer, which form low-pressure regions and further produce condensation, are analyzed and clarified under different operating conditions. It is found that the proposed method is efficient to limit the condensation in the impeller inducer, keep the compactness of the compressor, and maintain a high cycle efficiency.

Hemodynamic functions and blood viscosity in surface hypothermia

1978 ◽  
Vol 235 (2) ◽  
pp. H136-H143 ◽  
Author(s):  
R. Y. Chen ◽  
S. Chien
Keyword(s):  
Body Temperature ◽  
Blood Viscosity ◽  
Flow Resistance ◽  
Plasma Viscosity ◽  
Low Flow ◽  
Flow State ◽  
Surface Cooling ◽  
Plasma Loss ◽  
Pulmonary Flow ◽  
Anesthetized Dogs

Hemodynamic functions and blood viscosity changes in hypothermia (core approximately 25 degrees C) were studied in 14 pentobarbital-anesthetized dogs subjected to surface cooling. The viscosity of blood (eta B) increased progressively to 173% of that at 37 degrees C when body temperature was lowered to 25 degrees C. The increase in blood viscosity was caused by: a) the direct effect of low temperature on plasma viscosity, b) hemoconcentration as a result of plasma loss, and c) the low-flow (low-shear) state induced by hypothermia. A larger portion of the increased viscosity was caused by the low-flow state in hypothermia. The systemic flow resistance (SFR) increased to 271% of control, and this was attributable about equally to the increases in blood viscosity and systemic vascular hindrance (SFR/eta B). Similarly, the viscosity of blood contributed significantly to raising the pulmonary flow resistance. The relative constancy of mixed venous O2 saturation suggests that the cardiac output at low body temperature is generally adequate to meet the metabolic needs

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