Model Calculations on Micropump Using Reciprocating Motion of Magnetic Material Ball

2014 ◽  
Author(s):  
Hiroshige Kumamaru ◽  
Hayata Fujiwara ◽  
Yoshihisa Nomura ◽  
Kazuhiro Itoh
Keyword(s):  
Experimental Data ◽  
Magnetic Material ◽  
Flow Rate ◽  
Maximum Flow ◽  
Outer Diameter ◽  
Reciprocating Motion ◽  
Model Calculations ◽  
Flow Rates ◽  
Pump Head ◽  
Inner Diameter

The authors are developing a micropump which combines reciprocating motion of a magnetic material ball in a pumping channel and four passive check valves. An additional experiment has been performed for one combination of the ball outer diameter and the channel inner diameter, and results of this experiment are presented in this paper. Including the previous experiments performed by the authors, the maximum pump head of ∼620 mm and the maximum flow rate of ∼7.5 mL/min have been obtained in the present micropump. Also, in this study, model calculations have been performed in order to predict the pump performance, i.e. the relation between pump head and flow rate. Calculated flow rates agree well with experimental data for larger gaps between the ball outer diameter and the pumping-channel inner diameter; however, calculated flow rates are larger than the experimental data for smaller gaps. Therefore, it is necessary to improve the calculation models, in particular by calculating leak flow rate in the pumping channel as a flow through a nozzle instead of that through an orifice.

Studies on Micropump/Minipump Using Rotational Motion of Magnetic Material Balls

2013 ◽  
Author(s):  
Hiroshige Kumamaru ◽  
Fuma Sakata ◽  
Akira Ohue ◽  
Kazuhiro Itoh ◽  
Yuji Shimogonya
Keyword(s):  
Magnetic Material ◽  
Flow Rate ◽  
Cross Sections ◽  
Rotational Motion ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Numerical Analyses ◽  
Closed Channel ◽  
Pump Head ◽  
Inner Diameter

Experiments and numerical analyses have been performed on micropumps/minipumps using rotational motion of magnetic material balls. In the pumps, magnetic material balls and nonmagnetic materials balls rotate in a closed channel loop, and a part of the balls acts as a piston and the remaining part of the balls serves as a valve. Experiments have been carried out on two pumps, i.e. a smaller pump and a larger pump with channel cross-sections of ∼1 mm and ∼2 mm inner diameter, respectively. The maximum flow rate achieved and the maximum pump head obtained are ∼500 μl/min and ∼70 Pa, respectively, for the smaller pump, and ∼2000 μl/min and ∼150 Pa, respectively, for the larger pump. Numerical analyses have been performed by dividing the pumping loop into a piston channel and a valve channel. The numerical analyses overestimate the flow rate obtained in the experiments, except for the region of larger pump heads in the larger pump.

Optimization of an Innovative Rotary Shaft Pump (RSP)

2006 ◽  
Vol 128 (6) ◽  
pp. 1281-1288 ◽  
Author(s):  
Jacob C. Allen ◽  
Phillip M. Ligrani
Keyword(s):  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Maximum Flow ◽  
Performance Data ◽  
Outer Diameter ◽  
Hydraulic Efficiency ◽  
Rotary Pump ◽  
Optimal Arrangement ◽  
Pump Performance ◽  
Pump Head

This paper describes the optimization of rotary shaft pump performance, which is accomplished by comparing the performance of four different centrifugal rotary pump configurations: hooked blades pump, backward-curved blades ID=12.7mm pump, contoured base pump, and backward-curved blades ID=19.1mm pump. Each of these devices utilizes a unique and simple impeller design where the blades are directly integrated into a shaft with an outer diameter of 25.4mm. Presented for each pump are performance data including volumetric flow rate, pump head, and hydraulic efficiency. When pumping water, the most optimal arrangement with the hooked impeller blades produces a maximum flow rate of 3.22L∕min and a pump head as high as 0.97m.

An Experimental Study of the Flow of R-407C in an Adiabatic Spiral Capillary Tube

2009 ◽  
Vol 1 (4) ◽  
Author(s):  
M. K. Mittal ◽  
R. Kumar ◽  
A. Gupta
Keyword(s):  
Experimental Data ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Capillary Tube ◽  
Flow Characteristics ◽  
Flow Rates ◽  
Tube Test ◽  
Mass Flow Rates ◽  
R 134A

The objective of this study is to investigate the effect of coiling on the flow characteristics of R-407C in an adiabatic spiral capillary tube. The characteristic coiling parameter for a spiral capillary tube is the coil pitch; hence, the effect of the coil pitch on the mass flow rate of R-407C was studied on several capillary tube test sections. It was observed that the coiling of the capillary tube significantly reduced the mass flow rate of R-407C in the adiabatic spiral capillary tube. In order to quantify the effect of coiling, the experiments were also conducted for straight a capillary tube, and it was observed that the coiling of the capillary tube reduced the mass flow rate in the spiral tube in the range of 9–18% as compared with that in the straight capillary tube. A generalized nondimensional correlation for the prediction of the mass flow rates of various refrigerants was developed for the straight capillary tube on the basis of the experimental data of R-407C of the present study, and the data of R-134a, R-22, and R-410A measured by other researchers. Additionally, a refrigerant-specific correlation for the spiral capillary was also proposed on the basis of the experimental data of R-407C of the present study.

Prediction of Ingestion Through Turbine Rim Seals—Part II: Externally Induced and Combined Ingress

2010 ◽  
Vol 133 (3) ◽  
Author(s):  
J. Michael Owen
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Gas Turbines ◽  
Swirling Flows ◽  
Published Data ◽  
Flow Rates ◽  
Hot Gas ◽  
Predicted Values ◽  
Good Agreement

Ingress of hot gas through the rim seals of gas turbines can be modeled theoretically using the so-called orifice equations. In Part I of this two-part paper, the orifice equations were derived for compressible and incompressible swirling flows, and the incompressible equations were solved for axisymmetric rotationally induced (RI) ingress. In Part II, the incompressible equations are solved for nonaxisymmetric externally induced (EI) ingress and for combined EI and RI ingress. The solutions show how the nondimensional ingress and egress flow rates vary with Θ0, the ratio of the flow rate of sealing air to the flow rate necessary to prevent ingress. For EI ingress, a “saw-tooth model” is used for the circumferential variation of pressure in the external annulus, and it is shown that ε, the sealing effectiveness, depends principally on Θ0; the theoretical variation of ε with Θ0 is similar to that found in Part I for RI ingress. For combined ingress, the solution of the orifice equations shows the transition from RI to EI ingress as the amplitude of the circumferential variation of pressure increases. The predicted values of ε for EI ingress are in good agreement with the available experimental data, but there are insufficient published data to validate the theory for combined ingress.

Prediction of Ingestion Through Turbine Rim Seals—Part 2: Externally-Induced and Combined Ingress

2009 ◽  
Author(s):  
J. Michael Owen
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Gas Turbines ◽  
Swirling Flow ◽  
Published Data ◽  
Flow Rates ◽  
Hot Gas ◽  
Predicted Values ◽  
Good Agreement

Ingress of hot gas through the rim seals of gas turbines can be modelled theoretically using the so-called orifice equations. In Part 1 (ASME GT 2009-59121) of this two-part paper, the orifice equations were derived for compressible and incompressible swirling flow, and the incompressible equations were solved for axisymmetric rotationally-induced (RI) ingress. In Part 2, the incompressible equations are solved for non-axisymmetric externally-induced (EI) ingress and for combined EI and RI ingress. The solutions show how the nondimensional ingress and egress flow rates vary with Θ0, the ratio of the flow rate of sealing air to the flow rate necessary to prevent ingress. For EI ingress, a ‘saw-tooth model’ is used for the circumferential variation of pressure in the external annulus, and it is shown that ε, the sealing effectiveness, depends principally on Θ0; the theoretical variation of ε with Θ0 is similar to that found in Part 1 for RI ingress. For combined ingress, the solution of the orifice equations shows the transition from RI to EI ingress as the amplitude of the circumferential variation of pressure increases. The predicted values of ε for EI ingress are in good agreement with available experimental data, but there are insufficient published data to validate the theory for combined ingress.

A Water Lubricated Hybrid Thrust Bearing: Measurements and Predictions of Static Load Performance

2016 ◽  
Author(s):  
Luis San Andrés ◽  
Stephen Phillips ◽  
Dara Childs
Keyword(s):  
Flow Rate ◽  
Axial Load ◽  
Static Load ◽  
Outer Side ◽  
Outer Diameter ◽  
Test Rig ◽  
Predictive Tool ◽  
Thrust Bearings ◽  
Supply Pressure ◽  
Inner Diameter

Process fluid lubricated thrust bearings (TBs) in a turbomachine control rotor placement due to axial loads arising from pressure fields on the front shroud and back surface of impellers. To date, prediction of aerodynamic induced thrust loads is still largely empirical. Thus needs persist to design and operate proven thrust bearings and to validate predictions of performance derived from often too restrictive computational tools. This paper describes a test rig for measurement of the load performance of water lubricated hydrostatic/hydrodynamic thrust bearings operating under conditions typical of cryogenic turbo pumps. The test rig comprises of a rigid rotor composed of a thick shaft and two end collars. A pair of flexure-pivot hydrostatic journal bearings (38 mm in diameter) support the rotor and quill shaft connected to a drive motor. The test rig hosts two thrust bearings (8 pockets with inner diameter equal to 41 mm and outer diameter equal to 76 mm); one is a test bearing and the other is a slave bearing, both facing the outer side of the thrust collars on the rotor. The slave TB is affixed rigidly to a bearing support. A load system delivers an axial load to the test TB through a non-rotating shaft floating on two aerostatic radial bearings. The test TB displaces to impose a load on the rotor thrust collar and the slave TB reacts to the applied axial load. The paper presents measurements of the TB operating axial clearance, flow rate and pocket pressure for conditions of increasing static load (max. 3,600 N) and shaft speed to 17.5 krpm (tip speed 69.8 m/s) and for an increasing water supply pressure into the thrust bearings, max. 17.2 bar (250 psig). Predictions from a bulk flow model that accounts for both fluid inertia and turbulence flow effects agree well with recorded bearing flow rates (supply and exiting thru the inner diameter), pocket pressure and ensuing film clearance due to the imposed external load. The measurements and predictions show a film clearance decreasing exponentially as the applied load increases. The bearing flow rate also decreases, and at the highest rotor speed and lowest supply pressure, the bearing is starved of lubricant on its inner diameter side, as predicted. The measured bearing flow rate and pocket pressure aid to the empirical estimation of the orifice discharge coefficient for use in the predictive tool. The test data and validation of a predictive tool give confidence to the integration of fluid film thrust bearings in cryogenic turbo pumps as well as in other more conventional (commercial) machinery. The USAF Upper Stage Engine Technology (USET) program funded the work during the first decade of the 21st century.

scholarly journals HYDRAULIC ANALYSIS OF DRIP LATERALS WITH INSIDE WELDED PRESSURE COMPENSATING DRIPPERS

2019 ◽  
pp. 575-580
Author(s):  
Dimitar Georgiev ◽  
Veselin Karasinkerov
Keyword(s):  
Flow Rate ◽  
Drip Irrigation ◽  
Elastic Membrane ◽  
Outer Diameter ◽  
Operating Pressure ◽  
Engineering Project ◽  
Head Losses ◽  
Horizontal Part ◽  
Distribution Uniformity ◽  
Inner Diameter

Lately, the drip irrigation systems built with pressure compensating (PC) drippers (emitters) inside welded in the drip laterals, find more and more application in Bulgaria, Turkey, Greece and other countries having well-developed irrigation-based agriculture, especially where the ground is not flat but rather is of hilly nature. The main advantage of these systems is the provision of uniform flow rate along the laterals and batteries (blocks) in the whole drip systems irrespectively of the alteration of the operating pressure, and, besides, this allows long laterals to be designed. The recommended operating pressure starts from 0.5 – 1.0 atm and reaches 4 – 5 atm. Reaching equal drip flow rate in these systems is realized thanks to an elastic membrane with fixed strength parameters, located at the outlet of the nozzles in a specially arranged bed (nest) for this purpose. The advertisement of the applications of those nozzles in the company catalogs is very intensive but is it true for all types of pressure compensating drippers? In laboratory conditions we carried out hydraulic tests of drip laterals with inside welded pressure compensating drippers, cylinder type, in order to find out the head losses along the drip lateral. The laterals were with a nominal outer diameter 16 mm, inner diameter 13.8 mm, thickness of the wall 1.1 mm and flow rate 2.1 l/h, at intervals of 33 cm between the drippers, with lengths 60, 80 and 100 m. The results showed considerable head losses, with great deviations from the ones obtained by analytic way through formulas. For example, in a 100 m long lateral, the losses reach 60 to 75% of the applied operating pressure at the beginning of the lateral. Some specific data from the tests – in case of inlet pressure of 18, 20 and 25 m, the head losses are respectively 12, 14 and 17 m which means that in case of flat ground and such with back slope it is almost impossible to realize a length of 100 m and more of the lateral. All drippers will not operate at the horizontal part of the curve “pressure-flow rate” but at the transitional part of this curve. It follows from this that irrespectively of the pressure compensating action of those nozzles, this type of laterals will hardly find application in real conditions in the design of an engineering project for drip irrigation respecting the admissible coefficients of the distribution uniformity of the irrigation water. The same is valid for the other tested laterals as well. Sometimes, laying conventional type of laterals is more appropriate and brings better results. All this is due to the considerable minor head losses in those nozzles because of the sizable constriction of the cross section of the laterals by the nest (bed) of the membrane.

Single-Disk and Double-Disk Viscous Micropump

2004 ◽  
Author(s):  
Daniel B. Blanchard ◽  
Phillip M. Ligrani ◽  
Bruce K. Gale
Keyword(s):  
Flow Rate ◽  
Maximum Flow ◽  
Outer Diameter ◽  
Outlet Channel ◽  
Viscous Micropump ◽  
Pump Housing ◽  
Single Disk ◽  
Controlled Flow ◽  
Gap Height ◽  
Rhodamine Dye

The development and testing of two novel micropumps called the single-disk and double-disk viscous pumps are described. A single disk and the top pump housing, or two disks are separated by a small gap that forms a fluid passage. A wiper, that is the height of this gap, is placed between the two disks, or between the single disk and top pump housing, and extends from the outer diameter of the disk(s) to the center region of the disk(s). The movement of the disk(s) induces viscous stresses on the fluid that forces the fluid through the pump area above the single disk, or between the two disks. The wiper acts to “wipe” the fluid from the disk(s) toward the outlet channel. The fluid flow through the double-disk pump is visualized using a red Rhodamine dye that is injected into the fluid passage upstream of the pumping area. Experimental flow rate for the single-disk and double-disk pumps are obtained for a disk diameter of 2.381 mm, and a gap height of 103 μm. The maximum flow rates obtained are 0.74 ml/min and 2.1 ml/min for the single-disk and double-disk pumps, respectively, for a rotational speed of 5000 rpm. Advantages of the disk pumps include simplicity of design, planar structure, continuous flow, well controlled flow rate, and mixing characteristics.

Experimental Investigation to Enhance the Heat Transfer in Heat Exchanger by Made Groove in Outer Surface of the Inner Tube

2017 ◽  
Vol 5 (1) ◽  
pp. 1-15
Author(s):  
Zena K. Kadhim ◽  
Safaa Abed Mohammad
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flow Rate ◽  
Outer Surface ◽  
Hot Water ◽  
Outer Tube ◽  
Copper Tube ◽  
Working Fluid ◽  
Outer Diameter ◽  
Inner Diameter

This study deals with experimental work implementing to recover the benefit by changing the shape of the tube in heat exchanger (HE) and improving the heat transfer using water as the working fluid. The experimental tests were carried out in build and design a complete test system for counter flow heat exchanger. The tested system consisting of a copper tube with (1m) length (17.05) mm inner diameter (19.05) mm outer diameter, fixed concentric within the outer tube was made of a material PVC. With an “inner diameter (ID) (43 mm) and outer diameter (OD) (50 mm)” isolated from the outside by using insulating material to reduce heat loss. The modify tube was manufacture containing transverse grooves with the depth equivalent to the half thickness of the copper tube. The distance between the grooves on the outer surface of the copper tube is take as a ratio between (0.5, 1) from the outer tube diameter. The laboratory experiment use the hot water at a flow rate ranging between (1-5) LPM, passes in the inner copper tube. As well as the cooling water with the mass flow rate ranging between (3-7) LPM. Three temperatures were the hot fluid are the adoption of (40, 50 and 60) oC and (25) oC the cold fluid. The experiment result showed that the improvement for temperature difference ranging from (14.94 % to 43.2 %) for both corrugated tubes with respect to smooth tube.

scholarly journals Characteristics of mass transfer between gas-liquid phases in a higee reactor

2014 ◽  
Vol 20 (4) ◽  
pp. 523-530 ◽  
Author(s):  
Zhang Zhenzhen ◽  
Guo Kai ◽  
Luo Huijuan ◽  
Song Junnan ◽  
Qian Zhi
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Gas Absorption ◽  
Diffusion Reaction ◽  
Flow Rates ◽  
Rotating Speed ◽  
Liquid Phases ◽  
Calculation Results

In the absorption process of gas-liquid phases in Rotating Packed Bed (RPB), the liquid flow on packing was assumed to be film-flow. Based on Higbie?s penetration theory, the diffusion-reaction model in RPB was introduced to calculate the rate of gas absorption. Taking CO2 (10%)+N2(90%) gas mixture and N-methyldiethanolamine (MDEA) aqueous solution as objects, the experiments of gas absorption were carried out at different gas flow rates, rotating speeds, temperatures, liquid flow rates and MDEA mass concentrations. The experimental data were compared with calculation results to found a good agreement in the rotating speed range of 400-1100r/min. In this range, the rate of decarburization was in direct proportion to rotating speed, temperature and liquid flow rate, and inversely proportion to gas flow rate and MEDA mass concentration. The maximum deviation between experimental data and calculation results was 10%. Beyond the rotating speed of 1100 r/min, the rate of decarburization was dependent on the dynamic balance of gas-liquid system. In this area, the rate of decarburization was inversely proportion to rotating speed.

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