The Optimum Groove Geometry for Spiral Groove Viscous Pumps

1990 ◽  
Vol 112 (2) ◽  
pp. 409-414 ◽  
Author(s):  
Yuichi Sato ◽  
Kyosuke Ono ◽  
Akihiko Iwama
Keyword(s):  
Differential Equation ◽  
Flow Rate ◽  
Groove Width ◽  
Design Parameters ◽  
Width Ratio ◽  
Maximum Pressure ◽  
Spiral Groove ◽  
Clearance Ratio ◽  
Viscous Pump ◽  
Outflow Rate

The optimum geometries of disk and cylindrical sprial groove viscous pumps to provide the maximum pressure or flow rate are investigated theoretically. The geometrical design parameters, such as the groove angle, groove to ridge clearance ratio, groove width ratio and ridge clearance ratio, are considered as functions of meridional coordinate. Results are obtained from the solution of a differential equation for the smoothed overall pressure distribution of a spiral groove viscous pump. It is found that outflow rate increases with the increase of groove to ridge clearance ratio λ, and that for each value of λ there exist “optimum” values of groove angle and groove width ratio, which give a maximum outflow rate. However, the increase of λ decreases the ridge clearance.

Performance Characteristics of Shrouded Rayleigh-Step and Spiral Groove Viscous Pumps

1992 ◽  
Vol 114 (3) ◽  
pp. 499-503 ◽  
Author(s):  
Yuichi Sato ◽  
J. D. Knight
Keyword(s):  
Flow Rate ◽  
Performance Characteristics ◽  
Design Parameters ◽  
Spiral Groove ◽  
Viscous Pump

In this paper the optimum geometrical configurations of a shrouded Rayleigh-step and a spiral groove viscous pump are analyzed. Then their performance characteristics are compared. The geometries and film shapes of these viscous pumps are optimized with respect to flow rate and the design parameters are summarized graphically. The flow rate of the optimized spiral groove viscous pump is approximately 5–10 percent greater than that of the optimized shrouded Rayleigh-step viscous pump.

Analysis of Viscous Pumps With Shrouded Rayleigh-Steps Using Compressible Fluid

1988 ◽  
Vol 110 (4) ◽  
pp. 597-601 ◽  
Author(s):  
Yuichi Sato ◽  
Kyosuke Ono ◽  
Naoki Moriguchi
Keyword(s):  
Flow Rate ◽  
Compressible Fluid ◽  
Pressure Difference ◽  
Maximum Flow ◽  
Compressible Fluids ◽  
Maximum Flow Rate ◽  
Frictional Torque ◽  
Spiral Groove ◽  
Viscous Pump

The paper describes an analysis of viscous pumps with shrouded Rayleigh-steps using compressible fluids. The optimum pump geometry for the maximum flow rate is presented. Frictional torque is examined for the optimized pump geometry. Finally the characteristics of the pump proposed in this paper are compared with those of spiral groove viscous pumps which are frequently used. Consequently the viscous pump with Rayleigh-steps has greater flow rate and higher pressure difference.

Multi-objective optimization of squirrel cage fan for range hood based on Kriging model

2021 ◽  
pp. 095440622199586
Author(s):  
Qianhao Xiao ◽  
Jun Wang ◽  
Boyan Jiang ◽  
Weigang Yang ◽  
Xiaopei Yang
Keyword(s):  
Flow Rate ◽  
Optimization Design ◽  
Volume Flow Rate ◽  
Kriging Model ◽  
Volume Flow ◽  
Design Parameters ◽  
Multi Objective Optimization ◽  
Nsga Ii ◽  
Multi Objective ◽  
Squirrel Cage

In view of the multi-objective optimization design of the squirrel cage fan for the range hood, a blade parameterization method based on the quadratic non-uniform B-spline (NUBS) determined by four control points was proposed to control the outlet angle, chord length and maximum camber of the blade. Morris-Mitchell criteria were used to obtain the optimal Latin hypercube sample based on the evolutionary operation, and different subsets of sample numbers were created to study the influence of sample numbers on the multi-objective optimization results. The Kriging model, which can accurately reflect the response relationship between design variables and optimization objectives, was established. The second-generation Non-dominated Sorting Genetic algorithm (NSGA-II) was used to optimize the volume flow rate at the best efficiency point (BEP) and the maximum volume flow rate point (MVP). The results show that the design parameters corresponding to the optimization results under different sample numbers are not the same, and the fluctuation range of the optimal design parameters is related to the influence of the design parameters on the optimization objectives. Compared with the prototype, the optimized impeller increases the radial velocity of the impeller outlet, reduces the flow loss in the volute, and increases the diffusion capacity, which improves the volume flow rate, and efficiency of the range hood system under multiple working conditions.

Study on Silo Pressure by Consider Storage Materials Density Changed along the Height

2012 ◽  
Vol 517 ◽  
pp. 797-800
Author(s):  
Zhi Yong Yang ◽  
Shun Hu Liu ◽  
Song Zhao ◽  
Jun Hu ◽  
Zeng Chan Lu
Keyword(s):  
Differential Equation ◽  
Density Stratification ◽  
Maximum Pressure ◽  
Actual Case ◽  
Storage Materials ◽  
Pressure Calculation ◽  
The Difference

The difference existed between results of silos pressure calculation and the actual case, because the influence of density stratification was not taken into consideration. The aim of this paper was to obtain silo pressure calculating formula by consider of storage materials density stratified. To this end, we assume that the density was continuous changed along the height and differential equation of the storage materials pressure was established. By compared the results calculated from the equation with the results calculated from the code, it is found that the maximum pressure increased. The results showed density stratified is an import factor for silo pressure calculation and the equation obtained in this paper can provide references for the theory of silo pressure calculation.

The Biomimetic Shark Skin Optimization Design Method for Improving Lubrication Effect of Engineering Surface

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Yan Lu ◽  
Meng Hua ◽  
Zuomin Liu
Keyword(s):  
Coefficient Of Friction ◽  
Optimization Design ◽  
Design Method ◽  
Theory Model ◽  
Tribological Performance ◽  
Design Parameters ◽  
Width Ratio ◽  
Textured Surface ◽  
Shark Skin ◽  
Biomimetic Surface

Nature has long been an important source of inspiration for mankind to develop artificial ways to mimic the remarkable properties of biological systems. In this work, a new method was explored to fabricate a biomimetic engineering surface comprising both the shark-skin, the shark body denticle, and rib morphology. It can help reduce water resistance and the friction contact area as well as accommodate lubricant. The lubrication theory model was established to predict the effect of geometric parameters of a biomimetic surface on tribological performance. The model has been proved to be feasible to predict tribological performance by the experimental results. The model was then used to investigate the effect of the grid textured surface on frictional performance of different geometries. The investigation was aimed at providing a rule for deriving the design parameters of a biomimetic surface with good lubrication characteristics. Results suggest that: (i) the increase in depression width ratio Λ decreases its corresponding coefficient of friction, and (ii) the small coefficient of friction is achievable when Λ is beyond 0.45. Superposition of depth ratio Γ and angle's couple under the condition of Λ < 0.45 affects the value of friction coefficient. It shows the decrease in angle decreases with the increase in dimension depth Γ.

scholarly journals Taking into Account Outer Hydrodynamic Pressure in Differential Equation of Variable Flow Rate Fluid Flow for Distributive Pressure Pipelines

2012 ◽  
Vol 7 (1) ◽  
pp. 13-22
Author(s):  
Volodymyr V. Cherniuk
Keyword(s):  
Differential Equation ◽  
Fluid Flow ◽  
Flow Rate ◽  
Hydrodynamic Pressure ◽  
Variable Flow

Abstract In the differential equation of variable flow rate fluid flow a component which takes into account outer hydrodynamic pressure is introduced. The variables of the equation are expressed in terms of full operating head and in terms of independent distance along the axis of the stream, i. e. this equation is reduced to a singlevariable equation.

scholarly journals ANALISIS AERODINAMIKA PADA PERMUKAAN BODI KENDARAAN MOBIL LISTRIK GASKI (GANESHA SAKTI) DENGAN PERANGKAT LUNAK ANSYS 14.5

2017 ◽  
Vol 5 (2) ◽  
Author(s):  
Yudi Prihadnyana ◽  
Gede Widayana ◽  
Kadek Rihendra Dantes
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Body Modification ◽  
The Body ◽  
Vehicle Body ◽  
Maximum Pressure ◽  
Air Velocity ◽  
Electric Cars ◽  
Minimum Pressure ◽  
Electric Car

Dengan perkembangan teknologi yang semakin maju bentuk dari bodi sebuah kendaraan sangatlah diperhitungkan untuk mencapai tujuan-tujuan tertentu. Untuk itu, dilakukan analisis Aerodinamika pada pemukaan bodi mobil listrik gaski dengan menggunakan perangkat lunak Ansys 14.5, yang bertujuan untuk mengetahui aliran fluida dan nilai koefisient drag pada mobil listrik Gaski bodi standar dan modifikasi. Setelah proses analisis dilakukan, didapatkan hasil velocity udara maksimum body standar sebesar 17,4324 m/s dan body modifikasi sebesar 17,7321 m/s dan pressure maksimum yang terjadi pada mobil listrik Gaski body standar sebesar 83,2143 Pa, dan minimum sebesar -189,879 Pa. sedangkan pressure maksimum yang terjadi pada mobil listrik Gaski body modifikasi sebesar 83,2143 Pa. dan minimum pressure diperoleh -182,128 Pa. nilai Koefisient drag dari mobil listrik Gaski body standar sebesar 0,00474 sedangkan pada body modifikasi sebesar 0,00407. Dari hasil peneletian tersebut didapatkan bahwa setalah dilakukan modifikasi pada bodi mobil listrik gaski terdapat beberapa perubahan diantaranya terjadi peningkatan kecepatan laju aliran udara atau velocity udara meningkat 1,72 % sedangkan tekanan yang diterima oleh bodi setelah dimodifikasi menurun 1,39 % dan Nilai koefisien drag pada mobil listrik gaski dapat diturunkan 14,14 % setelah dimodifikasi.Kata Kunci : kata kunci : Aerodinamika, aliran fluida, bodi kendaraan, With the technological development of the more advanced form of the body of a vehicle is very calculated to achieve certain goals. For that purpose, Aerodynamic analysis was performed on the electric car body surface by using Ansys 14.5 software, which aims to find out the fluid flow and coefficient value of drag on electric car Gaski standard body and modification. After the analysis process is done, the result of the maximum air velocity of the standard body is 17,4324 m / s and body modification of 17,7321 m / s and the maximum pressure happened to electric car Gaski body standard equal to 83,2143 Pa, 189,879 Pa. While the maximum pressure that occurs on electric cars Gaski body modification of 83.2143 Pa. And the minimum pressure obtained -182.128 Pa. Coefficient value of drag from electric car Gaski body standard of 0,00474 while at body modification equal to 0,00407. From the results of the research was found that after modification on the body of electric car gaski there are some changes such as increase the speed of air flow rate or air velocity increased by 1.72%, while the pressure received by the body after modification decreased 1.39% and the value of drag coefficient on Electric car gaski can be derived 14.14% after modified.keyword : Keywords : Aerodynamic, fluid flow rate, Vehicle body.

Deep Hole Honing Based on Squeeze Film Damping Technology

2009 ◽  
Vol 76-78 ◽  
pp. 252-257
Author(s):  
Tian Biao Yu ◽  
Ya Dong Gong ◽  
Wan Shan Wang
Keyword(s):  
Differential Equation ◽  
Experimental Result ◽  
Squeeze Film ◽  
Design Parameters ◽  
Improve Quality ◽  
Deep Hole ◽  
Squeeze Film Damper ◽  
Squeeze Film Damping ◽  
Hole Machining

In order to improve quality of deep hole machining, a new method of deep hole honing based on squeeze film damping technology is put forward. For analysis effect on damper parameters on honing quality, motion differential equation of honing spindle with a squeeze film damper (SFD) is established according to D' Alembert principle and according simulations are studied. Spindle of deep hole honing with a SFD is designed based on the result of simulations and experiments are carried on. Experimental result shows that SFD with reasonable design parameters has excellent damping function to honing spindle, and it can make the vibration of honing spindle reduced 20%～30% and the quality of deep hole machining improved 10%～20%.

Development of a Latching Valve for Micro-Chem-Lab™

1999 ◽  
Author(s):  
C. Channy Wong ◽  
Douglas R. Adkins ◽  
Ronald P. Manginell ◽  
Gregory C. Frye-Mason ◽  
Peter J. Hesketh ◽  
...  
Keyword(s):  
Power Consumption ◽  
Gas Phase ◽  
Flow Rate ◽  
Integrated System ◽  
Dead Volume ◽  
Design Parameters ◽  
Working Fluid ◽  
Driving Voltage ◽  
Magnetic Actuation ◽  
Phase Detection

Abstract An integrated microsystem to detect traces of chemical agents (μChemLab™) is being developed at Sandia for counter-terrorism and nonproliferation applications. This microsystem has two modes of operation: liquid and gas phase detection. For the gas phase detection, we are integrating these critical components: a preconcentrator for sample collection, a gas chromatographic (GC) separator, a chemically selective flexural plate wave (FPW) array mass detector, and a latching valve onto a single chip. By fabricating these components onto a single integrated system (μChemLab™ on a chip), the advantages of reduced dead volume, lower power consumption, and smaller physical size can be realized. In this paper, the development of a latching valve will be presented. The key design parameters for this latching valve are: a volumetric flow rate of 1 mL/min, a maximum hold-off pressure of 40 kPa (6 psi), a relatively low power, and a fast response time. These requirements have led to the design of a magnetically actuated latching relay diaphragm valve. Magnetic actuation is chosen because it can achieve sufficient force to effectively seal against back pressure and its power consumption is relatively low. The actuation time is rapid, and valve can latch in either an open or closed state. A corrugated parylene membrane is used to separate the working fluid from internal components of the valve. Corrugations in the parylene ensure that the diaphragm presents minimum resistance to the actuator for a relativley large deflection. Two different designs and their performance of the magnetic actuation have been evaluated. The first uses a linear magnetic drive mechanism, and the second uses a relay mechanism. Preliminary results of the valve performance indicates that the required driving voltage is about 10 volts, the measured flow rate is about 50 mL/min, and it can hold off pressure of about 5 psi (34 kPa). Latest modifications of the design show excellent performance improvements.

Dynamic Characteristics Analysis of NuScale in Frequency Domain

2021 ◽  
Author(s):  
Jingrui Yang ◽  
Qian Ma ◽  
Lingtong Han ◽  
Peiwei Sun
Keyword(s):  
Frequency Domain ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Dynamic Characteristics ◽  
Water Desalination ◽  
Design Parameters ◽  
Mechanism Analysis ◽  
Secondary Loop ◽  
Calculation Results

Abstract NuScale is a small nuclear reactor that relies on natural circulation. Its modular production and inherent safety can not only be used to generate electricity in some remote areas, but also provide energy for water desalination and regional heating. However, the dynamic characteristics of the NuScale are different from those of the traditional PWRs because of its passive characteristic. Therefore, it is necessary to study and analyze the system dynamic characteristics of NuScale. The NuScale PWR model is established based on MATLAB&Simulink. It includes point-reactor kinetics model with six groups delayed neutrons, coolant system and steam generator system. The model is established based on the conservation equations of mass, energy and momentum. And the correctness of the model is verified by the comparison between the steady-state calculation results and the design parameters. Transient calculation results are verified by mechanism analysis. To evaluate the dynamic characteristics of NuScale, the sine function changes with different frequencies in reactor reactivity and feedwater mass flow rate are introduced. The amplitude and phase responses of reactor power, secondary loop steam pressure, secondary loop mass flow rate, secondary loop steam temperature, and coolant average temperature are recorded. Then the Bode plot can be drawn with amplitude and phase responses in different frequencies. To evaluate the NuScale dynamic characteristics, frequency domain analysis is performed.

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