Identification of design parameters for spool-type restrictors

This study presents the identification method of design parameters for single-action cylindrical spool-type restrictors of hydrostatic bearing. These parameters include restriction parameter, spool displacement parameter, and spring preload. The flow rates, inlet pressures, and outlet pressures are measured to be utilized for parameter identification of single-action cylindrical spool-type restrictors by using experimental equipment. This equipment-like an open-type planar hydrostatic bearing supports a worktable for changing recess pressure by changing apply load. Then, design parameters can be identified from the measurements of the inlet pressure, the recess pressure, average temperature, and the flow rate for each restrictor by using minimizing total error square between measured and identified quantities of flow rates. An identification method with experiments for single-action cylindrical spool-type restrictors of hydrostatic bearing is presented and designed. Also, the influences of design parameters on flow rate of single-action cylindrical spool-type restrictors are studied by experiments. The experimental equipment used in this study is our design, which can be used for all types of restrictors and hydrostatic bearings. This identification method for design parameters of the single-action cylindrical spool-type restrictors is reliable, valid, and accurate. The identification of design parameters is necessary for design change and calibration of single-action cylindrical spool-type.

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Investigations in Hydrostatic Planar Bearings Compensated by Tapered-Spool Restrictors I: Flow Rate

Journal of Mechanics ◽

10.1017/jmech.2015.41 ◽

2015 ◽

Vol 32 (1) ◽

pp. 63-69

Author(s):

Y. Kang ◽

H.-C. Cheng ◽

C.-W. Lee ◽

S.-Y. Hu

Keyword(s):

Flow Rate ◽

Analytical Method ◽

Pressure Difference ◽

Load Capacity ◽

Design Parameters ◽

Static Characteristics ◽

Static Stiffness ◽

Flow Rates ◽

Single Action ◽

Hydrostatic Bearing

ABSTRACTThis paper is former part of serial studies to investigate the influence of design parameters of tapered-spool type restrictors on static characteristics of hydrostatic bearing. The flow rates passing restrictors can determine the static characteristics of hydrostatic bearings. In this part an analytical method which includes formulas and solving is utilized to simulate dimensionless flow rate in both single-action and double-action tapered-spool restrictors. The numerical results illustrate the variations of flow rates with respect to the change of pressure and pressure difference, respectively. The findings give that the design parameters of tapered-spool restrictors and the useful range of recess pressure. The following part will depend on this paper results to study load capacity and static stiffness of hydrostatic bearing compensated by tapered-spool restrictor.

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Investigations in Hydrostatic Planar Bearings Compensated by Tapered-Spool Restrictors II: Load Capacity and Static Stiffness

Journal of Mechanics ◽

10.1017/jmech.2015.42 ◽

2015 ◽

Vol 32 (1) ◽

pp. 71-82

Author(s):

Y. Kang ◽

H.-C. Cheng ◽

C.-W. Lee ◽

S.-Y. Hu

Keyword(s):

Film Thickness ◽

Load Capacity ◽

Effective Area ◽

Design Parameters ◽

Static Characteristics ◽

Static Stiffness ◽

Single Action ◽

Hydrostatic Bearing ◽

Closed Type ◽

Maximum Stiffness

ABSTRACTThis study including two parts investigates the influence of design parameters of tapered-spool restrictors and hydrostatic planar bearing on static characteristics of load capacity and static stiffness. The former part provides guides for the design of single-action and double-action tapered-spool restrictors. This part provides design guides for planar hydrostatic bearing and for matching up with tapered-spool restrictor. The equations of flow continuity are utilized to determine the film thickness for open-type planar bearing and worktable displacement for closed-type planar bearing with respect to the recess pressure, respectively. The load capacity can be obtained by multiplying recess pressure by effective area of bearing pad. Furthermore, the static stiffness can be obtained by differentiating the recess pressure with respect to film thickness or worktable displacement. The finding results give that the usage range of recess pressure, and the availability ranges of design parameters of restrictor and bearing parameters. Which are found for getting the maximum stiffness.

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Identification of Characteristic Parameters for Hydrostatic Bearings

Journal of Mechanics ◽

10.1017/jmech.2014.91 ◽

2015 ◽

Vol 31 (2) ◽

pp. 227-240 ◽

Cited By ~ 1

Author(s):

Y. Kang ◽

S.-Y. Hu ◽

Y.-P. Chang ◽

T.-P. Wang

Keyword(s):

Flow Rate ◽

Design Parameters ◽

Characteristic Parameters ◽

Measure Flow Rate ◽

Hydrostatic Bearing ◽

Supply Pressure ◽

Hydrostatic Bearings ◽

Design Values

ABSTRACTThis study proposes a method to identify the characteristic parameters of hydrostatic bearing. When load or supply pressure changed, the inlet and outlet pressures of restrictor, flow rate and worktable displacement are examined for establish identification equations. The practical values of the characteristic parameters can be obtained by minimizing the differences between measure flow rate and identify flow rate. The differences between practical and design values of these parameters can be used to calibrate design parameters for satisfying the requirements.

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Maximizing the performance of pump inducers using CFD-based multi-objective optimization

Structural and Multidisciplinary Optimization ◽

10.1007/s00158-021-03108-6 ◽

2021 ◽

Vol 65 (1) ◽

Author(s):

Trupen Parikh ◽

Michael Mansour ◽

Dominique Thévenin

Keyword(s):

Flow Rate ◽

Tip Clearance ◽

Design Parameters ◽

Multi Objective Optimization ◽

Sweep Angle ◽

Flow Rates ◽

Blade Length ◽

Multi Objective ◽

Blade Thickness ◽

Wide Range

AbstractPump inducers are usually employed within a limited flow rate range since the performance is known to drop out significantly far from their design point. Therefore, finding an optimal geometry that ensures efficient operation for a relatively wide range of flow rates is challenging. The present study tackles this problem using multi-objective optimization to identify optimal inducer configurations, delivering high performance for a wide flow range. 3D RANS single-phase turbulent simulations were performed using the $$k-\omega$$ k - ω turbulence model. The optimization was done by employing the Non-dominated Sorting Genetic Algorithm (NSGA-II) coupled with computational fluid dynamics (CFD). An established in-house flow optimization library (OPAL++) was used to automatically control the numerical simulations. The objective is to optimize the inducer geometrical parameters to simultaneously maximize the efficiency and pressure head curves, considering different flow rates, i.e., 80% (part-load), 100% (nominal), and 150% (overload) of the optimal flow rate for the considered pump. The optimization involves 8 most relevant design parameters, i.e., the axial blade length, blade sweep angle, blade pitch, hub taper angle, tip clearance gap, blade thickness at the hub, blade thickness at the tip, and the number of blades. A total of 5178 simulations over 37 generations have been needed to get a Pareto front containing 5 optimal configurations. This article discusses quantitatively the influence of each geometrical parameter on flow behavior and inducer performance. The results reveal in general that blade length, blade sweep angle, tip clearance gap, and blade thickness should be kept low for the considered application; inducers with high hub taper angles and 3 blades lead to optimal performance.

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Pumping Schedule Optimization in Acid Fracturing Treatment by Unified Fracture Design

Energies ◽

10.3390/en14238185 ◽

2021 ◽

Vol 14 (23) ◽

pp. 8185

Author(s):

Rahman Lotfi ◽

Mostafa Hosseini ◽

Davood Aftabi ◽

Alireza Baghbanan ◽

Guanshui Xu

Keyword(s):

Flow Rate ◽

Computational Method ◽

Sensitivity Analyses ◽

Design Parameters ◽

Well Performance ◽

Fracture Geometry ◽

Flow Rates ◽

Fracture Width ◽

Acid Fracturing ◽

Lower Permeability

Acid fracturing simulation has been widely used to improve well performance in carbonate reservoirs. In this study, a computational method is presented to optimize acid fracturing treatments. First, fracture geometry parameters are calculated using unified fracture design methods. Then, the controllable design parameters are iterated till the fracture geometry parameters reach their optimal values. The results show higher flow rates are required to achieve optimal fracture geometry parameters with larger acid volumes. Detailed sensitivity analyses are performed on controllable and reservoir parameters. It shows that higher flow rates should be applied for fluids with lower viscosity. Straight acid reaches optimal conditions at higher flow rates and lower volumes. These conditions for retarded acids appear to be only at lower flow rates and higher volumes. The study of the acid concentration for gelled acids shows that both flow rate and volume increase as the concentration increases. For the formation with lower permeability, a higher flow rate is required to achieve the desired larger fracture half-length and smaller fracture width. Further investigations also show that the formation with higher Young’s modulus requires decreasing the acid volume and increasing the optimal flow rate, while the formation with higher closure stress requires increasing the acid volume and decreasing the flow rate.

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Exergy Optimization of a Novel Combination of a Liquid Air Energy Storage System and a Parabolic Trough Solar Collector Power Plant

Journal of Energy Resources Technology ◽

10.1115/1.4042415 ◽

2019 ◽

Vol 141 (8) ◽

Cited By ~ 7

Author(s):

Shahram Derakhshan ◽

Mohammadreza Khosravian

Keyword(s):

Energy Storage ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Solar Collector ◽

Design Parameters ◽

Parabolic Trough ◽

Flow Rates ◽

Mass Flow Rates ◽

Parabolic Trough Solar Collector

In this paper, a parabolic trough solar collector (PTSC) plant is combined with a liquid air energy storage (LAES) system. The genetic algorithm (GA) is used to optimize the proposed system for different air storage mass flow rates. The roundtrip exergy ratio is considered as the objective function and pressures of six points and mass flow rates of five points are considered as design parameters. The effects of some environmental and key parameters such as different radiation intensities, ambient temperatures, output pressures of the second compressor, and mass flow rates of the collectors fluid on the exergy ratio are investigated. The results revealed that the system could produce 17526.15 kJ/s (17.5 MW) power in high demands time and 2233.48 kJ/s (2.2 MW) power in low demands time and the system shows that a value of 15.13% round trip exergy ratio is achievable. Furthermore, the exergy ratio decreased by 5.1% when the air storage mass flow rate increased from 10 to 15 kg/s. Furthermore, the exergy ratio decreases by increasing the collectors inside fluid mass flow rate or by decreasing radiation intensity.

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Modeling of a Passive-Valve Piezoelectric Micro-Pump: A Parametric Study

Micromachines ◽

10.3390/mi11080752 ◽

2020 ◽

Vol 11 (8) ◽

pp. 752

Author(s):

Akam Aboubakri ◽

Vahid Ebrahimpour Ahmadi ◽

Ali Koşar

Keyword(s):

Optimum Condition ◽

Flow Rate ◽

Attack Angle ◽

Design Parameters ◽

Operating Voltage ◽

Flow Rates ◽

Micro Pump ◽

Length Width ◽

External Power ◽

Optimum Width

Piezoelectric micro-pumps offer many applications and could provide considerable flow rates in miniature systems. This study parametrically investigates the effects of major parameters, namely the length, width and attack angle of valves, piezoelectric length, and applied voltage. The results show that these parameters significantly affect the performance of the designed micro-pump. Even though increasing the piezoelectric length and operating voltage raise the flow rate, the modification of valve dimensions is more efficient since these parameters do not rely on any external power. According to the obtained results, as the length of the working valves increases, the provided flow rate becomes larger. There is an optimum condition for the width and attack angle of the valves. This optimum width is not dependent on the flow rate. With the use of the attack angle and the length of the valves as design parameters, the studied design shows promising results.

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Hydraulic model of a water cooling system in a chemical plant

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19880788 ◽

1988 ◽

Vol 53 (4) ◽

pp. 788-806

Author(s):

Miloslav Hošťálek ◽

Jiří Výborný ◽

František Madron

Keyword(s):

Flow Rate ◽

Cooling System ◽

Cooling Water ◽

Graph Algorithm ◽

Automatic Generation ◽

Hydraulic Calculation ◽

Return Flow ◽

Flow Rates ◽

Pressure Losses ◽

Controlled Flow

Steady state hydraulic calculation has been described of an extensive pipeline network based on a new graph algorithm for setting up and decomposition of balance equations of the model. The parameters of the model are characteristics of individual sections of the network (pumps, pipes, and heat exchangers with armatures). In case of sections with controlled flow rate (variable characteristic), or sections with measured flow rate, the flow rates are direct inputs. The interactions of the network with the surroundings are accounted for by appropriate sources and sinks of individual nodes. The result of the calculation is the knowledge of all flow rates and pressure losses in the network. Automatic generation of the model equations utilizes an efficient (vector) fixing of the network topology and predominantly logical, not numerical operations based on the graph theory. The calculation proper utilizes a modification of the model by the method of linearization of characteristics, while the properties of the modified set of equations permit further decrease of the requirements on the computer. The described approach is suitable for the solution of practical problems even on lower category personal computers. The calculations are illustrated on an example of a simple network with uncontrolled and controlled flow rates of cooling water while one of the sections of the network is also a gravitational return flow of the cooling water.

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Geometrical Optimization of a Venturi-Type Microbubble Generator Using CFD Simulation and Experimental Measurements

Designs ◽

10.3390/designs5010004 ◽

2021 ◽

Vol 5 (1) ◽

pp. 4

Author(s):

Dillon Alexander Wilson ◽

Kul Pun ◽

Poo Balan Ganesan ◽

Faik Hamad

Keyword(s):

Water Flow ◽

Flow Rate ◽

Cfd Simulation ◽

Air Flow ◽

Bubble Diameter ◽

Diameter Ratio ◽

Experimental Measurements ◽

Cfd Model ◽

Flow Rates ◽

Throat Diameter

Microbubble generators are of considerable importance to a range of scientific fields from use in aquaculture and engineering to medical applications. This is due to the fact the amount of sea life in the water is proportional to the amount of oxygen in it. In this paper, experimental measurements and computational Fluid Dynamics (CFD) simulation are performed for three water flow rates and three with three different air flow rates. The experimental data presented in the paper are used to validate the CFD model. Then, the CFD model is used to study the effect of diverging angle and throat length/throat diameter ratio on the size of the microbubble produced by the Venturi-type microbubble generator. The experimental results showed that increasing water flow rate and reducing the air flow rate produces smaller microbubbles. The prediction from the CFD results indicated that throat length/throat diameter ratio and diffuser divergent angle have a small effect on bubble diameter distribution and average bubble diameter for the range of the throat water velocities used in this study.

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Comparison of different models to calculate the viscosity of biogas and biomethane in order to accurately measure flow rates for conformity assessment

Scientific Reports ◽

10.1038/s41598-021-81052-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Karine Arrhenius ◽

Oliver Büker

Keyword(s):

Binary Mixtures ◽

Flow Rate ◽

Correction Method ◽

Gas Mixtures ◽

Conformity Assessment ◽

Flow Rates ◽

Unknown Composition

AbstractThe study presents an optimised method to correct flow rates measured with a LFE flowmeter pre-set on methane while used for gas mixtures of unknown composition at the time of the measurement. The method requires the correction of the flow rate using a factor based on the viscosity of the gas mixtures once the composition is accurately known. The method has several different possible applications inclusive for the sampling of biogas and biomethane onto sorbent tubes for conformity assessment for the determination of siloxanes, terpenes and VOC in general. Five models for the calculation of the viscosity of the gas mixtures were compared and the models were used for ten binary mixtures and four multi-component mixtures. The results of the evaluation of the different models showed that the correction method using the viscosity of the mixtures calculated with the model of Reichenberg and Carr showed the smallest biases for binary mixtures. For multi-component mixtures, the best results were obtained when using the models of Lucas and Carr.

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