Rotor Design and Optimization in Internal Lobe Pumps

1997 ◽  
Vol 50 (11S) ◽  
pp. S133-S141 ◽  
Author(s):  
Giovanni Mimmi ◽  
Paolo Pennacchi
Keyword(s):  
Flow Rate ◽  
Performance Comparison ◽  
Definite Function ◽  
Pump Design ◽  
Design And Optimization ◽  
Performance Indexes ◽  
New Type ◽  
Improved Performance ◽  
Lobe Pump ◽  
Rotor Curvature

The topic of this paper is the design of internal lobe pumps and their optimization which is based on specific performance indexes. Internal lobe pumps can be classified as different types depending on the shape of the lobe of the outer rotor. First, the design of internal lobe pumps with elliptical, sinusoidal, and polycircular lobe profiles is considered. The latter is a new type of lobe profile with special shape whose curvature follows a definite function. Then we introduce the performance indexes used for the comparison. Some of these indexes, such as the flow rate irregularity, are commonly used for performance comparison, while others, such as the specific slipping and the rotor curvature, are particularly suitable in this case. The comparisons are made with the circular type that had been analyzed by the authors in previous papers (see eg, Mimmi, Pannacchi, and Savi (1996), Internal Lobe Pump Design, Mechanics in design - Proc CSME Forum ’96, SA Meguid (ed), Toronto, Ontario, Canada). It is not easy to univocally state the superiority of one type with respect to the others, however, it is possible to notice that elliptical and polycircular types are comparable to the circular ones in terms of flow rate irregularity, but have improved performance in terms of specific slipping and rotor curvature.

INTERNAL LOBE PUMP DESIGN

1997 ◽  
Vol 21 (2) ◽  
pp. 109-121 ◽  
Author(s):  
G. Mimmi ◽  
P. Pennacchi
Keyword(s):  
Flow Rate ◽  
Design Parameters ◽  
Specific Flow ◽  
Pump Design ◽  
Positive Displacement ◽  
Performance Indexes ◽  
Rotor Profile ◽  
Main Components ◽  
Definition Of ◽  
Lobe Pump

The subject of this paper is the theoretical analysis of the internal lobe pump which is a particular type of positive displacement rotary pump. The main components of the pump are the rotors: usually the outer one is characterised by lobes with circular shape, while the inner rotor profile is determined as conjugate to the other. For this reason the first topic presented here is the definition of the geometry of the rotors starting from the design parameters. The choice of these parameters is subject to some limitations in order to avoid inner rotor undercutting and to limit the pressure angle between the rotors. Now we will consider the design optimisation. The first step is the determination of the instantaneous flow rate as a function of the design parameters. This allows us to calculate two performance indexes commonly used for the study of positive displacement pumps: the flow rate irregularity and the specific flow rate. These indexes are used to optimise the design of the pump and to obtain the sets of optimum design parameters. Finally further considerations are presented regarding the calculation and the use of other performance indexes, the specific slipping and the rotor curvature, which are particularly suitable for giving more elements for the analysis of this case.

Flow Rate Regularity in Rotary Trochoidal-Lobe Pumps

1994 ◽  
Author(s):  
G. Mimmi ◽  
P. Pennacchi
Keyword(s):  
Flow Rate ◽  
Distinctive Feature ◽  
Pump Design ◽  
Instantaneous Flow ◽  
Positive Displacement ◽  
Involute Gear ◽  
Gear Pumps ◽  
Points Of View ◽  
Lobe Pump ◽  
Instantaneous Flow Rate

Abstract This paper analyses a particular type of rotary positive-displacement pumps with lobes having epitrochoidal flanks, whose distinctive feature is that of providing a strictly constant geometric instantaneous flow rate. The pump design is analysed from geometric and kinematical points of view. Then the behavior of this type of lobe pump is compared with that of involute gear pumps.

Research on an axial-mounted dual magnetostrictive material rods-based electro-hydrostatic actuator

2021 ◽  
pp. 1045389X2110145
Author(s):  
Yuchuan Zhu ◽  
Chang Liu ◽  
Yunze Song ◽  
Long Chen ◽  
Yulei Jiang ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Flow Rate ◽  
Flow Distribution ◽  
Maximum Flow ◽  
Magnetostrictive Material ◽  
Simulation Techniques ◽  
Motion State ◽  
New Type ◽  
Output Characteristics ◽  
Active Rectification

In this paper, an electro-hydrostatic actuator driven by dual axial-mounted magnetostrictive material rods-based pumps (MMPs) with a new type of active rectification valve is designed in the current study. Based on flow distribution of the active rectification valve and driving energy provided by two MMPs, the actuator can output continuous and bidirectional displacement. By establishing a mathematical model of the actuating system, using simulation techniques, the change rule of hydraulic cylinder’s motion state caused by different driving signals are studied and analyzed. Test equipment platform is constructed in the laboratory to test the output characteristics and confirm the feasibility of the new concept. The experimental results indicate that the maximum flow rate can reach approximately 2.7 L·min−1, while the operating frequency is 180 Hz.

scholarly journals Design and optimization of the concept of a passenger train storage system

2019 ◽  
Vol 261 ◽  
pp. 02002
Author(s):  
Lucian Cucu ◽  
Marilena Stoica ◽  
Ionel Simion ◽  
Gina Florica Stoica
Keyword(s):  
European Union ◽  
Public Transportation ◽  
Storage System ◽  
Transportation System ◽  
The European Union ◽  
Passenger Train ◽  
Design And Optimization ◽  
Safe Storage ◽  
Railroad Transportation ◽  
New Type

The aim of this paper is to design a passenger train storage system. It concerns with the idea of safe storage in public transportation. The design consists of developing a new type of storage system complying with the standards of the European Union (EU) that can improve the railroad transportation system.

The Effect of Air Injection Method on the Airlift Pump Performance

2012 ◽  
Vol 134 (11) ◽  
Author(s):  
Dong Hu ◽  
Chuan-Lin Tang ◽  
Shu-Peng Cai ◽  
Feng-Hua Zhang
Keyword(s):  
Flow Rate ◽  
Volume Flow Rate ◽  
Low Cost ◽  
Air Injection ◽  
Water Volume ◽  
Pump Design ◽  
Pump Performance ◽  
Dimensionless Equation ◽  
Measurement Results ◽  
Injection Methods

With simple structure, excellent reliability, low cost, no restriction at depth of water, and easy control and operation, airlift pumps have special advantage in borehole hydraulic jet mining, river dredging and deep sea mining. To clarify the mechanism and process of action of air injection methods on air lift performance, and to enhance lifting capacity, the pump performance of a small airlift system in transporting river sands is investigated experimentally in the present study. The results are as the follows. The influences of air exit ports on water volume flow rate, mass flow rate of solids and lifting efficiency are studied and found to be very low when the number of air exit ports exceeds 3. The pump design show best pumping capability for water and solids at higher air flow rates, but the lifting efficiency is then very low. In addition, a dimensionless equation which describes the flows in the pipe is presented based on the Bernoulli equation, and compared with measurement results in the dimensionless form, which are nearly in good agreement with each other for all the arrangements of air exit ports and are basically contained within ±18% of the theoretical curve. The results are important for understanding the mechanism of airlift pumps and enriching multiphase flow theory.

CFD Modeling of Transient Flow Phenomena in an Axial Flow VAD

2007 ◽  
Author(s):  
Alexandrina Untaroiu ◽  
Amy L. Throckmorton ◽  
Houston G. Wood ◽  
Paul E. Allaire
Keyword(s):  
Blood Flow ◽  
Transient Flow ◽  
Axial Flow ◽  
The Body ◽  
Cfd Modeling ◽  
Ventricular Assist ◽  
Pump Design ◽  
Design And Optimization ◽  
Wide Range ◽  
Cfd Analyses

A ventricular assist device (VAD) effectively relieves the workload from a native heart, which has been weakened by disease, and increases blood flow supplied to the body to maintain normal physiologic function. The device must be able to operate over a wide range of conditions. Designed to operate at a single, best-efficiency operating point, it must frequently perform at off-design conditions due to a fluctuating flow rate demanded by the human body and a time varying flow within the pump, due to the beating of the native heart. The design and optimization of a blood pump is a challenging and complex process. Pump design equations are used to estimate the initial dimensions of the pump regions. Computational fluid dynamics (CFD) analyses are then performed to optimize the blood flow path according to specific design criteria under steady flow conditions [1].

scholarly journals PERFORMANCE COMPARISON OF LASTON AC-WC BASED ON AGGREGATE GRADATION SPECIFICATIONS

2018 ◽  
Vol 2 (02) ◽  
pp. 151
Author(s):  
Devi Yulita Metasari ◽  
Akhmad Hasanuddin ◽  
Dewi Junita Koesoemawati
Keyword(s):  
Flow Rate ◽  
Outer Layer ◽  
Performance Comparison ◽  
High Flow ◽  
T Test ◽  
Aggregate Gradation ◽  
Significant Difference ◽  
Bitumen Content ◽  
Asphalt Content ◽  
Paired T Test

Laston AC-WC is the outer layer of the pavement that is directly related to the outside, so a strong mixture is required. One of the major effects is the aggregate gradation.This experiment aims to find out the comparison of Laston AC-WC performance between mixtures used aggregat egradation above and below the restriction zone. Each mixture used 6 variations of asphalt content and there were 3 specimens on each variation of bitumen content. The asphalt contents used were 5,5%; 6%; 6,5%; 7%; 7,5% dan 8%. From the results of the experiments, the mixture with the aggregate above the restriction zone at 7% and 7.5% asphalt content had a density value of 2.13 gr / cc and 2.12 gr / cc respectively; VMA value of 15.49% and 15.91%; VFA values ​​of 80.48% and 79.98%; VIM value of 3.16% and 3.18%; stability value of 3013.58 kg and 2332.57 kg; flow value of 2.47 mm and 2.18 mm; as well as MQ values ​​of 1222.25 kg / mm and 1184.59 kg / mm. While on the mixture with the aggregate under the restriction zone in the asphalt content of 7% and 7.5% obtained density value of 2.11 gr / cc and 2.14 gr / cc; VMA value of 17.21% and 16.3%; VFA value of 71.21% and 78.65%; VIM value of 4.99% and 3.49%; stability value of 2518,75 kg and 3234,72 kg; flow values ​​of 2 mm and 2.07 mm; as well as the MQ value of 1259.37 kg / mm and 1623.54 kg / mm. From the results are analyzed Paired T test and found that the value of flow has a significant difference. The high flow rate was found in the mixture with the aggregate above the restriction zone at 7% asphalt content, so this mixture is more durable due to good flexibility. Laston AC-WC merupakan lapisan terluar perkerasan yang berhubungan langsung dengan keadaan luar, sehingga dibutuhkan campuran yang kuat. Salah satu yang berpengaruh besar adalah gradasi agregat yang digunakan. Penelitian ini bertujuan untuk mengetahui perbandingan kinerja laston AC-WC antara campuran yang menggunakan gradasi di atas dengan di bawah daerah larangan. Penelitian ini dilakukan terhadap campuran laston AC-WC. Masing-masing campuran menggunakan 6 variasi kadar aspal dan terdapat 3 benda uji pada setiap kadar aspal. Kadar aspal yang digunakan adalah 5,5%; 6%; 6,5%; 7%; 7,5% dan 8%. Dari hasil penelitian, campuran dengan agregat di atas daerah larangan pada kadar aspal 7% dan 7,5% memiliki nilai density berturut-turut sebesar 2,13 gr/cc dan 2,12 gr/cc; nilai VMA sebesar 15,49% dan 15,91%; nilai VFA sebesar 80,48% dan 79,98%; nilai VIM sebesar 3,16% dan 3,18%; nilai stabilitas sebesar 3013,58 kg dan 2332,57 kg; nilai flow sebesar 2,47 mm dan 2,18 mm; serta nilai MQ sebesar 1222,25 kg/mm dan 1184,59 kg/mm. Sedangkan pada campuran dengan agregat di bawah daerah larangan pada kadar aspal 7% dan 7,5% didapatkan nilai density sebesar 2,11 gr/cc dan 2,14 gr/cc; nilai VMA sebesar 17,21% dan 16,3%; nilai VFA sebesar 71,21% dan 78,65%; nilai VIM sebesar 4,99% dan 3,49%; nilai stabilitas sebesar 2518,75 kg dan 3234,72 kg; nilai flow sebesar 2 mm dan 2,07 mm; serta nilai MQ sebesar 1259,37 kg/mm dan 1623,54 kg/mm. Dari hasil tersebut dilakukan analisa Uji T Berpasangan dan didapatkan bahwa nilai flow memiliki perbedaan yang signifikan. Nilai flow yang tinggi terdapat pada campuran dengan agregat di atas daerah larangan pada kadar aspal 7%, sehingga campuran ini lebih tahan lama dikarenakan memiliki kelenturan yang baik.

scholarly journals hydrocyclone Performance Comparison between Recycled Single Stage and Double Stage Hydrocyclones

2020 ◽  
Vol 21 (3) ◽  
pp. 51-55
Author(s):  
Mohannad A. Raheem ◽  
Raghad F. Qassim
Keyword(s):  
Flow Rate ◽  
Separation Efficiency ◽  
Performance Comparison ◽  
Single Stage ◽  
Feed Concentration ◽  
Modes Of Operation ◽  
Split Ratio ◽  
Inlet Flow Rate ◽  
Water Feed ◽  
The Cost

   This research presents a comparison of performance between recycled single stage and double stage hydrocyclones in separating water from water/kerosene emulsion. The comparison included several factors such as: inlet flow rate (3,5,7,9, and 11 L/min), water feed concentration (5% and 15% by volume), and split ratio (0.1 and 0.9). The comparison extended to include the recycle operation; once and twice recycles. The results showed that increasing flow rate as well as the split ratio enhancing the separation efficiency for the two modes of operation. On the contrary, reducing the feed concentration gave high efficiencies for the modes. The operation with two cycles was more efficient than one cycle. The maximum obtained efficiencies were 97% and 97.5% at 5% concentration, 11 L/min, and 0.9 split ratio for twice recycled single stage and double stage hydrocyclones, respectively. The pressure drop was the same for the two modes of operation. It was concluded that using recycled single stage hydrocyclone was more economical since it reduced the cost of additional hydrocyclone.

Static Characteristics of a Rectangular Hydrostatic Thrust Bearing With a Self-Controlled Restrictor Employing a Floating Disk

1993 ◽  
Vol 115 (2) ◽  
pp. 307-311 ◽  
Author(s):  
S. Yoshimoto ◽  
Y. Anno ◽  
M. Fujimura
Keyword(s):  
Flow Rate ◽  
Applied Load ◽  
Thrust Bearing ◽  
Static Characteristics ◽  
Hydrostatic Bearing ◽  
Supply Pressure ◽  
Wide Range ◽  
Bearing Stiffness ◽  
New Type ◽  
Very High

This paper proposes a new type of a self-controlled restrictor which can achieve a very high bearing stiffness in hydrostatic bearings. This self-controlled restrictor employs a floating disk to control the mass flow rate of the oil entering the bearing clearance according to changes of the applied load. Furthermore, a hydrostatic bearing with this restrictor can theoretically achieve an infinite stiffness when the mass of a floating disk is assumed to be zero. The static characteristics of a rectangular hydrostatic thrust bearing with this self-controlled restrictor are theoretically and experimentally investigated. It was consequently shown that the proposed hydrostatic thrust bearing can achieve a very high stiffness (nearly infinite stiffness) in a very wide range of applied load independent of supply pressure.

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