pump design
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Author(s):  
Gustavo Koury Costa ◽  
Nariman Sepehri

Abstract Pump-controlled single-rod hydraulic actuators have long been the subject of intensive research towards building valve-less, more efficient systems. The main challenge is to deal with the uneven flows into and out of the differential cylinders. Over the past few years, several hydraulic circuits providing flow compensation have been proposed using hydrostatic pumps with identical input and output flows. However, one alternative solution would be to use a pump, whose input/output flow ratio matches the area ratio of the differential cylinder. Typical design and prototyping of the so-called asymmetrical pumps have been well reported previously. In this paper, we theoretically study the flow behaviour in a common design of asymmetrical axial-piston pumps and demonstrate some serious internal flow characteristics that can drastically limit the performance and range of operation of these pumps. Cavitation is the main problem to be addressed, and cannot be overlooked because of the very nature of the pump design.


2021 ◽  
Author(s):  
Jinjiang Xiao ◽  
Chidirim Ejim

Abstract This paper describes a new electrical submersible pump (ESP) design concept to overcome the challenges of applications in slim well completions or thru-tubing deployment. The housing of the conventional pump is removed, allowing the pump impellers to have a larger diameter. The impact of this design change on pump hydraulic performance is assessed in this paper. Downhole ESPs operate in environments where space is limited radially. This is especially the case for slim completions or for thru-tubing rigless deployment. To provide the required rate and total dynamic head, the current approach is to use permanent magnetic motors and operate the slim systems at rotational speed over the conventional speed of 3500-4000 RPM. High-speed operations require new pump stage designs to minimize erosion and vibration. This paper provides an alternative pump design, which removes the pump housing with the benefit of increasing the impeller tip diameter, and hence potentially reducing pump length and operational speed. To ensure the pump retains the well fluids, the diffusers are designed to be externally threaded with an O-ring feature. The centrifugal pump affinity laws are applied to evaluate the impact of removing the pump housing and increasing the impeller outside diameter. A typical ESP housing wall thickness is about 0.18-0.25 inch. With the housing removed, the incremental space available for the impeller tip to occupy is increased by 0.36-0.5 inch. Analysis shows that, for the same pump speed as a conventional pump with a housing, a housingless pump will increase the head generated by 23-32%, and the rate capacity about 36-51%, depending on the pump series. In general, the smaller the pump outer diameter, the greater the flow and head capacity increase. This is because the available space due to removing the housing becomes a considerable size of the impeller tip diameter for the smaller series pumps. The elimination of pump housing enables impellers with a larger diameter to be used to generate more head per stage. In comparison to a conventional pump of the same outside diameter, and providing the same amount of total dynamic head, the housingless pump can have fewer stages and a shorter length or operate at a reduced speed. The reduced length can help mitigating pump-bending stress for installation in deviated or horizontal wells. The reduction in required operating speeds will reduce pump wears, heat generation and vibration. The housingless ESPs have applications for slim well completions or thru-tubing deployments.


2021 ◽  
Vol 55 (6) ◽  
Author(s):  
M. Gokhan Günay ◽  
Ubade Kemerli

A novel nano-scale pump that can transport atoms or small molecules with a peristaltic motion is designed. It is proven by molecular-dynamics simulations that the introduced nano-pump design works properly. The designed nano-pump consists of one main carbon nanotube named the flow tube and two rotors where multi-walled carbon nanotubes are attached. The pumping of helium atoms by the designed peristaltic carbon nano-pump is investigated by molecular-dynamics simulations. For varying rotor speeds and blade counts, time-averaged velocity, temperature, and pressure results of pumped helium atoms are calculated, and relationships between them are modeled as polynomial surfaces. The results showed that rotor frequency increases the velocity of helium linearly and the temperature and pressure of helium non-linearly. Furthermore, the blade count of the proposed mechanism does not substantially affect the velocity as per the previous studies in the literature.


Heliyon ◽  
2021 ◽  
pp. e08608
Author(s):  
Gonzalo Chiriboga ◽  
Santiago Capelo ◽  
Pablo Bunces ◽  
Carla Guzmán ◽  
Jonathan Cepeda ◽  
...  

2021 ◽  
pp. 082585972110527
Author(s):  
Ruth Isherwood ◽  
Amy Forsyth ◽  
Anne Wilson

Background Dihydrocodeine can be more effective in the management of headache due to brain tumor than other opioids. It can be used as a subcutaneous infusion, but at present, there is little available data to support its use in combination with other medicines in a syringe pump. Aim This project aimed to establish physical stability data for the use of dihydrocodeine with other drugs when combined in a syringe pump. Design: Dihydrocodeine was combined in a syringe pump with either cyclizine, midazolam, or hyoscine butylbromide at different doses chosen to represent routine clinical practice. Each drug combination was repeated twice—with 0.9% sodium chloride and with water for injections. Setting: The project was conducted in an independent hospice after seeking appropriate approvals to use the drugs for this purpose. Results Dihydrocodeine and midazolam appear compatible at when 0.9% sodium chloride is used as the diluent. Dihydrocodeine and cyclizine appeared compatible when either 0.9% saline or water for injections was used as the diluent. Dihydrocodeine and hyoscine butylbromide appeared compatible with either diluent at 24 hours. Conclusions Physical stability data has been described that will support the use of dihydrocodeine and other drugs that are commonly used to manage symptoms due to brain tumors at the end of life. This information will benefit patients and ensure that one syringe pump can be used where possible. Future work could expand on this data and explore the physical stability of three drug combinations in each syringe.


2021 ◽  
Vol 11 (21) ◽  
pp. 10177
Author(s):  
Vedrana Markučič ◽  
Mario Šavar ◽  
Severino Krizmanić ◽  
Bojan Biočina

In this paper, the design of a new type of heart pump is presented. The uniqueness of this pump concept is that the mechanical energy is transferred to the fluid by the rotation of flat disks without blades. Both theoretical and numerical analysis are used to determine the pump design parameters. The pump design parameters are calculated using the Navier–Stokes equations. The application of computational fluid dynamics is used to define the geometric design. The pump head and flow have to be within strictly defined limits to ensure normal blood circulation. The negative impact of the pump on the blood must be minimal (no stagnation and recirculation zones, shear stress in the acceptable range). It is also important to achieve the smallest possible pump volume. For the pump operating point of ∆p = 65 mmHg, Q = 5.43 L/min, and ω = 6000 rpm, the design parameters are inner radius R1 = 12 mm, outer radius R2 = 15 mm, the distance between disk of h = 1 mm, and the number of disks is n = 6. The shear stress in the rotor is in range 46–108 Pa and the pump residence time is 0.0194 s.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Hao Jia ◽  
Yuqi Wang ◽  
Zuchao Zhu ◽  
Xianghui Su ◽  
Zhenji Tang

Along with the pressing demand for the long-distance transportation of coarse particles in the deep-sea mining industry, evaluating the slurry pump’s passing through and erosive wear by studying the particle motion characteristics and the slurry behavior is becoming increasingly important. Research on the influence of leakage flow through the clearance and balancing devices on the motion characteristic of granular grain flow is of great significance but has been seldom studied. This study coupled the discrete element method with the CFD method to investigate the comprehensive effect of a double-stage slurry pump’s main flow and leakage flow on the motion characteristics of particles with a 10 mm diameter. Results show that the leakage flow occupation in main flow falls from 26%–27% to 8%–9% for the two stages, with the flow rate increasing from 80 m3/h to 200 m3/h. In the first stage with leakage, accumulation of coarse particles was observed at the impeller eye, which should be paid much attention to slurry pumps’ operation to eliminate the chance of blockage. In the nonleak situation, although the increment of the average kinetic energy of particles through the impeller is more significant than in the leak case, most of them dissipate primarily by more than 10% collision in the bowl diffuser. In the leak or nonleak case, the average kinetic energy of particles was more than twice through the first stage but only 1.1 times through the second stage. The selection of stages in the slurry pump design should consider the limitation of particle velocity improvement.


Author(s):  
MOHAMED EL GENDY ◽  
O. ANWAR BÉG ◽  
A. KADIR ◽  
M. N. ISLAM ◽  
D. TRIPATHI

Motivated by recent developments in bio-inspired medical engineering micro-scale pumps, in this paper, a three-dimensional sequential simulation of a peristaltic micro-pump is described to provide deeper insight into the hydromechanics of laminar, viscous flow in peristaltic propulsion. The Carreau and power-law models are employed for non-Newtonian behavior. The commercial software package ANSYS Fluent is utilized to conduct a numerical simulation of laminar peristaltic pump fluid dynamics, based on the finite volume method and steady space laminar solver. Details are provided for the geometric pump design (conducted with AUTOCAD), pre-processing (meshing) and necessary boundary conditions to simulate the peristaltic flow within the pump. Extensive visualization of velocity, pressure and vorticity contours is included. The present simulations provide a benchmark for future comparison with experimental studies and indeed more advanced numerical simulations with alternative non-Newtonian models. Applications of the study include biomimetic blood flow pumps, blood dialysis machines, micro-scale infusion pumps, etc.


2021 ◽  
pp. 039139882110525
Author(s):  
Akiko Oota-Ishigaki ◽  
Takashi Yamane ◽  
Daisuke Sakota ◽  
Ryo Kosaka ◽  
Osamu Maruyama ◽  
...  

Low-flow blood pumps rated under 1 L/min are emerging for new medical applications, such as hemofiltration in acute use. In those pumps, platelet adhesion and aggregation have to be carefully considered because of clogging risk in the filter part. To find an acceptable hemocompatibility that can be applied to low-flow centrifugal blood pump design, the platelet aggregation index, clogging on a micromesh filter, and the hemolysis index were investigated using a low-flow blood pump designed for hemofiltration use. We conducted circulation testing in vitro using fresh porcine blood and two centrifugal pumps with different impeller inlet shapes. The Negative Log Platelet Aggregation Threshold Index (NL-PATI), which reflects the ability of residual platelets to aggregate, and flow rate were measured during reflux for 60 min, and the Normalized Index of Hemolysis (NIH (g/20 min)) was calculated. In addition, blood cell clogging after reflux was observed on the micromesh filter by SEM, and the adhesion rate was calculated. Our results showed that the platelet clogging on the micromesh filter occurred when the average NL-PATI was greater than 0.28 and the average NIH (g/20 min) was greater than 0.01. In contrast, platelet clogging on the micromesh was suppressed when NL-PATI was less than 0.17 and the NIH (g/20 min) was less than 0.003. These values might be used as acceptable hemocompatibility of low-flow centrifugal blood pumps with suppressed platelet clogging for hemofiltration pumps.


2021 ◽  
Author(s):  
Anastasia Dmitrievna Musorina ◽  
Grigory Sergeyevich Ishimbayev

Abstract Under the present conditions of oil and gas production, which are characterized by mature production fields and the focus shifted towards digitalization of production processes and use of machine learning (ML) models, the issues related to the improvement of accuracy and consistency of the well operation control data are becoming increasingly important. As a result, SPD has successfully implemented the project of using annular pressure sensors in combination with machine learning models to control the well annular pressure as part of the field development program compliance. Under the field development program, echosounder and telemetry system readings are typically used to control the annular pressure and the dynamic flowing level. Echosounders, however, are not designed as measuring instruments, the accuracy of their readings being low and making it impossible to reliably evaluate the well's dynamic flowing level and annular pressure, as well as to achieve the well's maximum potential, and the telemetry systems used to measure the pump intake pressure may go wrong. This manuscript describes the approach to the producer well annular pressure assessment based on the machine learning model data. The machine learning (ML) model is a function of the target variable (bottom-hole pressure), which is predicted on the basis of the actual data: static parameters (well schematic, pump design) and dynamic parameters (annular and line pressures, flowrate). The input parameter interpretation results in the most probable value of the target variable based on the historic data.


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