scholarly journals Effect of Jetpump Throat Diameter and Secondary Discharge on Suction Pressure and Pump Efficiency

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Fatkhur Rohman Eka Candra Wijaya
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Pump Efficiency ◽  
Suction Pressure ◽  
Test Results ◽  
Low Speed ◽  
Mixing Chamber ◽  
Throat Diameter

The throat diameter is one of the main parts of the jetpump, the throat diameter is a mixing chamber which has the function of mixing low-speed secondary fluids with high-speed primary fluids. The purpose of this study was to determine the effect of the throat jetpump diameter with a variation of 7,9,11 mm and secondary discharge with a variation of 10,15,20 L / minute on the suction pressure and pump efficiency. The highest test results were variations in the throat diameter of 11 mm and secondary discharge of 20 L / minute with a net discharge of 3.8 L / minute, an average discharge of 23.8 L / minute, a suction pressure of -0.25 and an efficiency value pump by 50%, the larger the throat diameter the greater the flow rate obtained.

scholarly journals Investigating the pumping process of a resonance-vibrating pump for medium-depth boreholes

2008 ◽  
Vol 53 (No. 4) ◽  
pp. 172-181 ◽  
Author(s):  
I.A. Loukanov
Keyword(s):  
Resonance Frequency ◽  
Flow Rate ◽  
Ground Level ◽  
Preliminary Test ◽  
Degree Of Freedom ◽  
Pump Efficiency ◽  
Test Results ◽  
Resonance Vibrations ◽  
Experimental Findings ◽  
Mechanical Shaker

This paper deals with the pumping process of a resonance-vibrating pump, which utilizes the resonance vibrations of one degree-of-freedom oscillating system. The pump is powered by a mechanical shaker consisting of two counter rotating offset masses and operating in resonance. The study investigates the nature of the pumping process and conditions required to achieve pumping action. Equations for the flow rate, pressure developed at ground level or any height above it, the pump efficiency, and the power delivered by the shaker are derived. The analysis of the pumping process revealed that the flow rate of the pump may be maximized either by increasing the acceleration imparted on the oscillating system, and/or by reducing the resonance frequency. It was found that the pressure developed by the pump is independent of the depth of pumping, provided that the same acceleration is imparted, and its efficiency may be increased either by reducing the resonance frequency and/or by increasing the depth of pumping. The preliminary test results about the flow rate and pressure developed at ground level appeared to be close to the values predicted by the proposed theory. Based on the analysis of the theoretical and experimental findings it is concluded that the equations derived in this study may be employed in designing resonance vibrating pumps for a desirable flow rate, pressure, and efficiency in pumping water from a specified depth.

Performance of Small High Speed Cryogenic Pumps

1985 ◽  
Vol 107 (2) ◽  
pp. 197-203 ◽  
Author(s):  
Kenjiro Kamijo ◽  
Kunio Hirata
Keyword(s):  
High Speed ◽  
Rocket Engine ◽  
Pump Efficiency ◽  
Test Results ◽  
Flow Rates ◽  
High Head ◽  
Design Characteristics ◽  
Liquid Rocket ◽  
Reported Data ◽  
The Relationship

Several small cryogenic pumps for a liquid rocket engine have been made and tested. These pumps have a small impeller and are characterized by high speed and high head. The main design characteristics of these pumps are as follows: stage specific speeds of from 0.0319 to 0.0766, flow rates from 0.016 to 0.0525 m3/s, pressure rises from 4.9 to 26 MPa, rotational speeds from 16,500 to 80,000 rpm, and impeller diameters from 0.083 to 0.146 m. These pumps, when tested, showed higher efficiency even in the range of small stage specific speeds than any previously reported data on other pumps. This tendency was particularly striking with the two-stage pumps. With regard to pump efficiency measurement, it was made clear that adiabatic efficiency was utilizable for the present cryogenic pumps. The relationship between the adiabatic efficiency and ordinary efficiency was also confirmed by a brief calculation and test results.

scholarly journals Solar powered hybrid multilevel inverter fed induction motor using fuzzy proportional integral speed controller

2019 ◽  
Vol 23 (Suppl. 1) ◽  
pp. 391-402
Author(s):  
Mehmet Senol
Keyword(s):  
Induction Motor ◽  
High Speed ◽  
Multilevel Inverter ◽  
Test Results ◽  
Low Speed ◽  
Proportional Integral ◽  
Speed Controller ◽  
Integral Controller ◽  
Proportional Integral Controller ◽  
Solar Powered

In this paper, speed control of solar powered single phase hybrid multilevel inverter fed induction motor using fuzzy proportional integral controller is proposed. The proposed control system has been developed using MATLAB/SIMULINK. Performance of the proposed controller is tested in reference speed conditions with step change. The parameter analyzed for the proposed controller is steady-state error and settling time. This is compared with the proportional integral controller. Proposed speed controller is tested with two speed region such as low speed region and high speed region. In low speed region, speed command is varied from 40, 60, and 80 rad/s with 0.6 s step time. In high speed region, speed command is varied from 100, 120, and 140 rad/s with 0.6 s step time. Corresponding, performance parameters are measured and analyzed for both regions with proposed controller and proportional integral controller. From the test results, fuzzy proportional integral speed controlled hybrid multilevel inverter fed induction motor outperforms than proportional integral controller. Finally, the results are verified experimentally.

Validation of ATHLET Code by LOCA-Induced Pressure Wave Propagation Tests

2014 ◽  
Author(s):  
István Trosztel ◽  
Iván Tóth ◽  
György Ézsöl
Keyword(s):  
Wave Propagation ◽  
Flow Rate ◽  
Pressure Wave ◽  
High Speed ◽  
Low Frequency ◽  
Test Facility ◽  
Primary System ◽  
Pressure Waves ◽  
Test Results ◽  
System Pressure

Propagation of pressure waves inside the reactor vessel after a large break LOCA is an issue since it affects pressure drop across core internals and, as a result, induces stresses in different components, like core barrel, core structures and even fuel. For reactor safety analysis pressure wave propagation is traditionally performed by systems codes. However, strong dispersion among the calculated results calls for test results to validate the calculations. The pressure wave propagation following a larger LOCA is being systematically addressed by experiments in the PMK-2 integral-type test facility. In order to capture the high speed propagation of pressure waves special pressure transducers (capable to resolve the pressure variation with a frequency of 4 kHz) have been installed. The first four tests were conducted with rupture disks for opening the break, but a special quick opening valve will be installed for future tests, allowing the adjustment of the opening time between 12 and 50 ms. The paper presents results of validation of the ATHLET code by the test results. The low-frequency oscillation of the measured system pressure was shown to be caused by flow rate coming from the pressuriser that compensates mass lost via the break: the frequency of the oscillation was slightly under-predicted. The propagation of the first rarefaction wave from the top of the downcomer to the upper plenum is very well calculated by ATHLET: in spite of the first order discretisation no numerical diffusion can be observed. The calculated pressure differences between two different locations in the system are of primary interest, since they define the loads on primary system internals. ATHLET somewhat overestimates the amplitude of the pressure difference pulses, while it fairly well describes the frequency of oscillations. First analyses indicate an effect of the calculated break flow rate. ATHLET calculates a slower attenuation of the pressure oscillations as compared to test results. This can be the consequence of rigid walls assumed in the analysis. The tendency of increasing first pressure peak with increasing system pressure is well predicted by the code. In summary, it can be stated that ATHLET calculations produce slightly conservative results based on comparison with measured data.

scholarly journals Method for calculating actual capacity of single-stage long-stroke reciprocating compressors

2020 ◽  
Vol 4 (4) ◽  
pp. 9-15
Author(s):  
V. L. Yusha ◽  
◽  
S. S. Busarov ◽  
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Single Stage ◽  
Actual Performance ◽  
Low Speed ◽  
Air Compressor ◽  
Productivity Losses ◽  
Long Stroke

The article presents a generalized method for calculating the actual performance of low-speed longstroke air compressor stages of compression, based on determining the flow rate as a set of coefficients reflecting the influence of various factors on productivity losses. The method takes into account the design and operating features of low-speed long-stroke air compressor stages of compression and differs significantly from a similar method used to calculate high-speed stages of reciprocating compressors

Improvement of Suction Performance Using Splitter Impeller and Inducer

2017 ◽  
Author(s):  
K. Hayashi ◽  
S. Konno ◽  
M. Hayakawa ◽  
Y. Kawata
Keyword(s):  
Flow Rate ◽  
Industrial Applications ◽  
Flow Coefficient ◽  
The Other ◽  
Suction Pressure ◽  
Test Results ◽  
Pressure Condition ◽  
The Many ◽  
Suction Performance ◽  
Onset Of Cavitation

Suction performance is one of the most important characteristics of the industrial pump to keep the pump capability against the cavitation under the low suction pressure condition. Inducers have been developed to improve the suction performance of pumps. They are used for rocket turbo pumps and recently for many industrial applications. It is one of the competitiveness of the industrial pumps to downsize the scale with higher rotational speed by adopting inducer. The authors had proved that pump with splitter impeller with inducer can further improve the suction performance. The splitter impeller was specially designed to be resistant to the cavitation choke. The other very important requirement for the pump against cavitation is that it does not occur cavitation surge. The cavitation surge arises at the partial flow rate of the pump. In contrast to this the suction performance become better at the partial flow rate. So the precise compromise is necessary to satisfy these requirements. This paper presents the experimental and CFD results to improve and optimize the suction performance without generating cavitation surge. The many design and combination of splitter impeller and inducer are tested to get the better performance. The test results of pumps with different inlet flow coefficient are compared not only suction performance but also the onset of cavitation surge.

Re´sume´ of Compressor Research at the NACA Langley Laboratory

1961 ◽  
Vol 83 (3) ◽  
pp. 269-285 ◽  
Author(s):  
M. Savage ◽  
E. Boxer ◽  
J. R. Erwin
Keyword(s):  
Research Program ◽  
High Speed ◽  
Test Results ◽  
Low Speed ◽  
Cascade Testing ◽  
Transonic Cascade

This paper describes the compressor research program conducted at the NACA Langley Laboratory and highlights the significant developments obtained prior to the discontinuance of this program in 1957. Results of low speed, high speed, and transonic cascade testing are noted. Transonic and supersonic compressor test results and analyses are presented.

scholarly journals Operating Limitations of High-Speed Jet-Lubricated Ball Bearings

1976 ◽  
Vol 98 (1) ◽  
pp. 32-39 ◽  
Author(s):  
E. V. Zaretsky ◽  
H. Signer ◽  
E. N. Bamberger
Keyword(s):  
Contact Angle ◽  
Flow Rate ◽  
Parametric Study ◽  
High Speed ◽  
Ball Bearings ◽  
Test Results ◽  
Outer Race ◽  
Lubricant Flow ◽  
Thrust Load ◽  
Inner Race

A parametric study was performed with 120-mm bore angular-contact ball bearings having a nominal contact angle of 20 deg. The bearings either had an inner- or an outer-race land riding cage. Lubrication was by recirculating oil jets. The oil jets either had a single or dual orifice. Thrust load, speed, and lubricant flow rate were varied. Test results were compared with those previously reported and obtained from bearings of the same design which were under-race lubricated but run under the same conditions. Jet lubricated ball bearings were limited to speeds less than 2.5 × 106 DN. Bearings having inner-race land riding cages produced lower temperatures than bearings with outer-race land riding cages. For a given lubricant flow rate dual orifice jets produced lower bearing temperatures than single orifice jets. However, under-race lubrication produced under all conditions of operation lower bearing temperatures with no apparent bearing speed limitation.

Do You Name Speedy Objects Faster Than Slow Objects: SPEEDED NAMING OR NAMING SPEED? THE AUTOMATIC EFFECT OF OBJECT SPEED ON PERFORMANCE

2018 ◽  
Author(s):  
Moshe Shay Ben-Haim ◽  
Eran Chajut ◽  
Ran Hassin ◽  
Daniel Algom
Keyword(s):  
High Speed ◽  
Mental Representations ◽  
Reading Aloud ◽  
Naming Task ◽  
Naming Speed ◽  
Low Speed ◽  
Everyday Objects ◽  
Pictures And Words

we test the hypothesis that naming an object depicted in a picture, and reading aloud an object’s name, are affected by the object’s speed. We contend that the mental representations of everyday objects and situations include their speed, and that the latter influences behavior in instantaneous and systematic ways. An important corollary is that high-speed objects are named faster than low-speed objects despite the fact that object speed is irrelevant to the naming task at hand. The results of a series of 7 studies with pictures and words support these predictions.

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