Valveless Pump in Closed Loop Tube System

2014 ◽  
Vol 607 ◽  
pp. 561-564
Author(s):  
M. Mazwan Mahat ◽  
Izdihar Tharazi ◽  
Liyana Roslan ◽  
Mohd Fakrul Jasni

This research work aims to identify the characteristic of flow in valveless impedance pump which uses acoustic impedance mismatch to drive flow. The experimental setup mainly focuses on the elastic section connected between two ends of rigid tube. Fluid flow rate resulting from the pumping mechanism were measured at different supply voltage. Meanwhile, the volume flow rate (ml / min) in the elastic tube section were also determined based upon different pinch location and width using water as a working fluid. In order to achieve these parameters quantification, the experimental test rig was designed and the set of equipments were successfully assembled. Then, the measured parameters resulting from the experiment of the impedance pump are presented in significant findings of four curves plots. It is found that the maximum flow rate occurred at voltage setting equal to 4 V. Significantly, results obtained could beneficial future design as a mimics model for novel Ventricular Assist Device use in cardiac patient as well as further explanation about the factor that influence the characteristic of valveless impedance pump.

2014 ◽  
Vol 660 ◽  
pp. 932-936
Author(s):  
M. Mazwan Mahat ◽  
R.N. Izzati ◽  
Ilya Izyan Shahrul Azhar ◽  
Izdihar Tharazi

This paper aims to analyse the performance of impedance pump that uses energy mismatch to drive fluid flow. The experimental setup mainly focus to establish the relationship between the fluids flow rates in elastic tube section connected between two ends of solid tube and pinch mechanism location as well as fluid viscosity. Measurement of fluid flow rate or representation of its velocities resulting from the pumping mechanism is measured using two different supply voltage and constant pincher width. These measured parameters resulting from the pinch mechanism of the elastic tube section were varied at different pinch location along itsx-axis direction; divided into two main cases namely (1) 2 V and (2) 3 V at 40 mm to 140 mm pinch location. From the voltage variation, it is found that the maximum flow rate given by voltage 3.0 V at pinch location 40 mm while for the effect of viscosity, the highest flow rate is 93 ml/min. The profiles obtained revealed the characteristic of valve less pump to be the new model of new Ventricular Assist Device use in cardiac patient as well as further explanation about the factor that influence the characteristic of elastic tube.


2013 ◽  
Vol 393 ◽  
pp. 747-752 ◽  
Author(s):  
M. Mazwan Mahat ◽  
M. Arif Sulaiman ◽  
Chee Sheng Ow ◽  
Rosnadiah Bahsan ◽  
N. Merlisa Ali ◽  
...  

This paper summarises a study which aims to develop and analyze the performance of the valveless impedance pump. Mechanism of valveless impedance pump is to apply acoustic impedance mismatch in order to drive the flow and also consists of a flexible connection at the ends to the more rigid sections. Characteristics of liquid velocity and pressure at the pump base valveless impedance at various supply voltage and different frequencies have been discovered through experimentation. Secondly, this research also aims to discuss the effect volume flow rate (millitres / min) in the elastic tube impedance based on different parameters of the pump pinch. The variation of pinch location and pinch width are also available through the results of this study. This study begins with the design set up to use the software and followed by installing all equipment used for the experiments. Then, this study continues to get results and make an analysis of the impedance pump by experimentation. Results found that all the parameters used in this experiment affect the flow rate in the impedance pump. Additional experiments on the effect of the thickness of the flexible tube on the flow rate gave lower values when the flexible tube is relatively thicker.


Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 500
Author(s):  
Jian Chen ◽  
Wenzhi Gao ◽  
Changhai Liu ◽  
Liangguo He ◽  
Yishan Zeng

This study proposes the improvement of the output performance of a resonant piezoelectric pump by adding proof masses to the free ends of the prongs of a U-shaped piezoelectric resonator. Simulation analyses show that the out-of-phase resonant frequency of the developed resonator can be tuned more efficiently within a more compact structure to the optimal operating frequency of the check valves by adjusting the thickness of the proof masses, which ensures that both the resonator and the check valves can operate at the best condition in a piezoelectric pump. A separable prototype piezoelectric pump composed of the proposed resonator and two diaphragm pumps was designed and fabricated with outline dimensions of 30 mm × 37 mm × 54 mm. Experimental results demonstrate remarkable improvements in the output performance and working efficiency of the piezoelectric pump. With the working fluid of liquid water and under a sinusoidal driving voltage of 298.5 Vpp, the miniature pump can achieve the maximum flow rate of 2258.9 mL/min with the highest volume efficiency of 77.1% and power consumption of 2.12 W under zero backpressure at 311/312 Hz, and the highest backpressure of 157.3 kPa under zero flow rate at 383 Hz.


Author(s):  
Hyungki Shin ◽  
Junhyun Cho ◽  
Young-Jin Baik ◽  
Jongjae Cho ◽  
Chulwoo Roh ◽  
...  

Power generation cycle — typically Brayton cycle — to use CO2 at supercritical state as working fluid have been researched many years because this cycle increase thermal efficiency of cycle and decrease turbomachinery size. But small turbomachinery make it difficult to develop proto type Supercritical Carbon dioxide (S-CO2) cycle equipment of lab scale size. KIER (Korea Institute of Energy Research) have been researched S-CO2 cycle since 2013. This paper is about 60kWe scale and sub-kWe class turbo generator development for applying to this S-CO2 cycle at the lab scale. A design concept of this turbo-generator is to use commercially available components so as to reduce development time and increase reliability. Major problem of SCO2 turbine is small volume flow rate and huge axial force. High density S-CO2 was referred as advantage of S-CO2 cycle because it make small turbomachinery possible. But this advantage was not valid in lab-scale cycles under 100kW because small amount volume flow rate means high rotating speed and too small diameter of turbine to manufacture it. Also, high inlet and outlet pressure make huge axial force. To solve these problem, KIER have attempt various turbines. In this paper, these attempts and results are presented and discussed.


2005 ◽  
Vol 127 (4) ◽  
pp. 752-760 ◽  
Author(s):  
Danny Blanchard ◽  
Phil Ligrani ◽  
Bruce Gale

The development and performance of a novel miniature pump called the rotary shaft pump (RSP) is described. The impeller is made by boring a 1.168 mm hole in one end of a 2.38 mm dia shaft and cutting slots in the side of the shaft at the bottom of the bored hole such that the metal between the slots defines the impeller blades. The impeller blades and slots are 0.38 mm tall. Several impeller designs are tested over a range of operating conditions. Pump performance characteristics, including pressure rise, hydraulic efficiency, slip factor, and flow rate, are presented for several different pump configurations, with maximum flow rate and pressure rise of 64.9ml∕min and 2.1 kPa, respectively, when the working fluid is water. Potential applications include transport of biomedical fluids, drug delivery, total analysis systems, and electronics cooling.


2010 ◽  
Vol 03 (04) ◽  
pp. 473-491 ◽  
Author(s):  
S. K. PANDEY ◽  
DHARMENDRA TRIPATHI

The investigation is to explore the transportation of a viscoelastic fluid by peristalsis in a channel as well as in a circular cylindrical tube by considering Jeffrey-model. In order to apply the model to the swallowing of food-bolus through the oesophagus, the wave equation assumed to propagate along the walls is such that the walls contract in the transverse/radial direction and relax but do not expand further. Solutions have been presented in the closed form by using small Reynolds number and long wavelength approximations. The expressions of pressure gradient, volume flow rate and average volume flow rate have been derived. It is revealed on the basis of computational investigation that for a fixed flow rate, pressure decreases when the ratio of relaxation time to retardation time is increased. In both the channel and tubular flows, the pressure decreases on increasing the ratio of relaxation time to retardation time if the averaged flow rate is less than the maximum flow rate. It is also revealed that the maximum tubular flow rate is higher than that of the channel-flow. It is further found through the theoretical analysis that mechanical efficiency, reflux and local wall shear stress remain unaffected by viscoelastic property of the fluid modelled as Jeffrey-fluid.


2015 ◽  
Vol 76 (10) ◽  
Author(s):  
Muhamad Mazwan Mahat ◽  
Salmiah Kasolang ◽  
Izdihar Tharazi ◽  
R. Nazirul Izzati

 Impedance pump is a simple valveless pumping mechanism which typically used in viscosity measurement device to assist pumping of fluid. It is typically connected to an elastic tube in a circulatory system of a more rigid tube. In conventional mechanical circulatory support systems using rotary pump, the pumping mechanism was exposed to turbulent stresses. Hence,  this may cause damage to blood cells flowing through the impeller. There has been initial work on finding alternative solution using the impedance pump system. However,  substantial findings are not yet sufficient to fully understand the mechanism. The purpose of this research is to extend the investigation on impedance pump by specifically looking at the effect of structural parameters on the elastic tube and the flow behaviour. In this study, a closed loop impedance pump system was set up to demonstrate blood flow circulatory system where the mixture of glycerine and water was used as the working fluid. Three variables were regulated namely voltage, tube thickness, and tube length was used in order to get the flowrate of the working fluid. Based on the results, it was found that  tube thickness of 1 mm and a length of 200 mm had produced the highest flowrate in the region 75 ml/min.


Author(s):  
Christos Manopoulos ◽  
Sokrates Tsangaris ◽  
Dimitrios Mathioulakis

Net flow generation in valveless pumping, met in many physiological applications and recently in micropumping devices, constitutes an open fluid dynamics issue due to the complex interaction between the fluid medium and the flexible walls of the pump. In the context of the present experimental work, the conditions of the net flow generation are examined in a closed-loop horizontal valveless pump, which consists of a rigid and an elastic tube of equal diameters and lengths, and a pincher that forces the liquid within the tube to oscillate at Reynolds and Womersley numbers up to 7800 and 48, respectively. Pinching off as well as at the mid-length of the pump flexible tube, net flow is generated at certain pinching frequencies for which details are presented based on simultaneous recording of the pressure at the two tube junctions, the flow rate and the displacement of the pincher. Pinching off the mid-length of the pump at low pinching frequencies, net flow rate is practically null due to the almost identical pressure waveforms at the tube junctions, which vary in phase with the pincher motion. However, close to the first natural frequency of the hydraulic loop, the reflection of the pressure waves at the tube junctions combined with their increased phase difference cause high axial pressure gradients, which when they increase simultaneously with the squeezing of the tube, net flow rate maximization occurs. Pinching at the flexible tube mid-length area, nonzero net flow rates can also be generated, the sign of which changes when the pincher mid-point crosses the tube mid-length without being nullified.


2001 ◽  
Author(s):  
Hyeun Joong Yoon ◽  
Woo Young Sim ◽  
Sang Sik Yang

Abstract This paper presents the fabrication and test of a phase-change type micropump with two aluminum flap valves. This micropump consists of a pair of Al flap valves and a phase-change type actuator. The actuator is composed of a heater, a silicone rubber diaphragm and a working fluid chamber. The diaphragm is actuated by the vaporization and the condensation of the working fluid. The micropump is fabricated by the anisotropic etching, the boron diffusion and the metal evaporation. The dimension of the micropump is 8.5 mm × 5 mm × 1.7 mm. The forward and the backward flow characteristics of the flap valve illustrate the appropriateness as a check valve. Also, the flow rate of the micropump is measured. When the square wave input voltage of 10 V is applied to the heater, the maximum flow rate of the micropump is 6.1 μl/min at 0.5 Hz and the duty ratio of 60% for zero pressure difference.


Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6193
Author(s):  
Mohamed Fadl ◽  
Philip Eames

In this study, the thermal performance of latent heat thermal energy storage system (LHTESS) prototype to be used in a range of thermal systems (e.g., solar water heating systems, space heating/domestic hot water applications) is designed, fabricated, and experimentally investigated. The thermal store comprised a novel horizontally oriented multitube heat exchanger in a rectangular tank (forming the shell) filled with 37.8 kg of phase change material (PCM) RT62HC with water as the working fluid. The assessment of thermal performance during charging (melting) and discharging (solidification) was conducted under controlled several operational conditions comprising the heat transfer fluid (HTF) volume flow rates and inlet temperatures. The experimental investigations reported are focused on evaluating the transient PCM average temperature distribution at different heights within the storage unit, charging/discharging time, instantaneous transient charging/discharging power, and the total cumulative thermal energy stored/released. From the experimental results, it is noticed that both melting/solidification time significantly decreased with increase HTF volume flow rate and that changing the HTF inlet temperature shows large impacts on charging time compared to changing the HTF volume flow rate. During the discharging process, the maximum power output was initially 4.48 kW for HTF volume flow rate of 1.7 L/min, decreasing to 1.0 kW after 52.3 min with 2.67 kWh of heat delivered. Based on application heat demand characteristics, required power levels and heat demand can be fulfilled by employing several stores in parallel or series.


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