Micro Flow Sensor Based on Frequency Measurement of Micro Whistles

2012 ◽  
Vol 468-471 ◽  
pp. 2061-2064
Author(s):  
Yan Bin Di ◽  
Ying Miao
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Volume Flow Rate ◽  
Frequency Measurement ◽  
Flow Sensor ◽  
Fluid Properties ◽  
Micro Flow ◽  
The Difference ◽  
Rate Frequency ◽  
Geometrical Dimensions

In this work, several millimeter sized micro whistles have been tested as potential frequency analog gas flow sensors. The characteristic curves of the whistles were systematically investigated as a function of geometrical dimensions, the kind of gas applied, and temperature. Both a micro¬phone and a PVDF foil were employed to record the frequencies. The relation be¬tween oscillation frequency and volume flow rate only shows a weak function of fluid properties and temperature. At a given flow rate, the difference of argon and nitrogen is 120 Hz on average, which is corresponding to 1.4 %. For air flow at a given flow rate, frequency rises approximately 380 Hz (2.73 %) per 10 °C. This kind of micro whistle could be employed as gas flow sensor which is insensitive to fluid properties.

Turbine flow sensor for volume-flow rate verification in MR

1994 ◽  
Vol 32 (3) ◽  
pp. 410-417 ◽  
Author(s):  
Richard Frayne ◽  
David W. Holdsworth ◽  
Robert F. Smith ◽  
Reza Kasrai ◽  
Jan P. T. Larsen ◽  
...  
Keyword(s):  
Flow Rate ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Flow Sensor

scholarly journals Darcy–Boussinesq Model of Cilia-Assisted Transport of a Non-Newtonian Magneto-Biofluid with Chemical Reactions

2020 ◽  
Vol 10 (3) ◽  
pp. 1137 ◽  
Author(s):  
Ali Ahmad Farooq ◽  
Zahir Shah ◽  
Poom Kumam ◽  
Ebraheem O. Alzahrani ◽  
Meshal Shutaywi ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Vertical Channel ◽  
Boussinesq Model ◽  
Factors Affecting ◽  
Highly Nonlinear ◽  
The Difference ◽  
Geometrical Factors ◽  
Mixed Convective Flow

The model developed in this study presents a mathematical approach to the physiological transport of seminal liquid due to ciliary movements, which are attached with the lumen of the ductile efferent in the male reproductive system. The rheological properties of the seminal liquids were described using the Jeffrey liquid model. The problem described an electromagnetic mixed convective flow of a Jeffrey liquid through a vertical channel with heat and mass transfers. The effects of chemical reactions and the external heat generation were included in the formulation. The flow took place through an active porous medium (due to thick cilia mat and other deposits) and was influenced by the Lorentz magnetic force. Four basic conservation laws of mass, momentum, energy, and concentration were utilized in the mathematical modeling. These are highly nonlinear equations, which were simplified due to a physiologically valid approach known as LAT (lubrication approximation theory). Analytical solutions for temperature, concentration, and velocity profiles were evaluated. The expressions describing the pressure–volume flow rate relationships were also obtained. Analysis of various physical and geometrical factors affecting the pressure–volume (pumping) characteristics was also presented. One of the main findings of our study is that the difference between our calculated values of the flow rate and the estimated values of the flow rate in the ductile efferent was negligibly small. Moreover, our results can be implemented in the artificial cilia pumping systems in microchannels.

Experimental Analysis of Venturi-Tube Behavior in Wet Gas Conditions

2020 ◽  
Author(s):  
Olav Mehlum ◽  
Øyvind Hundseid ◽  
Lars E. Bakken
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Volume Fraction ◽  
Volume Flow Rate ◽  
Venturi Tube ◽  
Low Flow ◽  
Detailed Knowledge ◽  
Operation Conditions ◽  
Wet Gas ◽  
Compressor Inlet

Abstract Subsea wet gas compressors have been successfully in operation for approximately 5 years. Their use has proven to increase the recovery by approximately 10% and achieve a reliability up to 98%. Further developed and operation of subsea wet gas compression require detailed knowledge of compressor operability and how shift in operational conditions affect the compressor system. The compressors ability to handle wet gas is documented in detail for a gas volume fraction limited down to 0.90. The 4–5 last year of operation proves the wet gas concepts capability. As years pass by, well pressure and production rate declines which causes the compressor operation point to shift towards the high head and low flow (surge) area of the characteristics. In addition, compressor inlet transients increase due to pipe surge (slugs), requiring a robust control system to prevent instabilities, e.g. compressor surge. It is therefore vital to understand how the compressor inlet flow device behaves at different wet operation conditions. The article documents how a standard dry gas venturi tube behave at different wet gas operation conditions. The venturi is designed according to ISO5167-4 for dry gas conditions and is tested at the low-pressure air water compressor test rig at NTNU. The primary objective of the work has been to visualize the wet flow regime through the transparent venturi tube and to document the wet gas flow rate measurements by means of single-phase meters. The venturi tube is tested in a GMF range from 1 to 0.83 at an air volume flow rate of 1.3m3/s.

Unsteady Analysis of Microvalves With No Moving Parts

2007 ◽  
Vol 23 (1) ◽  
pp. 9-14 ◽  
Author(s):  
C.-T. Wang ◽  
T.-S. Leu ◽  
J.-M. Sun
Keyword(s):  
Unsteady Flow ◽  
Flow Rate ◽  
Reverse Flow ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Pressure Amplitude ◽  
Flow Conditions ◽  
Unsteady Flow Condition ◽  
The Difference ◽  
Moving Parts

AbstractNo-moving-parts valves (NMPV) pumps produce the net volume flow due to the difference of pressure resistances between forward and reverse flow of a microchannel structure. NMPV has been developed by a number of research groups. However, most of NMPV in these studies are designed and based on steady state flow conditions. Little data is available regarding the NMPV in unsteady flow conditions. In this study, the performances of NMPV under both steady and unsteady flow conditions are investigated numerically. The NMPV used in this study is a diffuser-type microchannel with diffuser angle of 20° because of its outstanding production of net volume flow. By a series of numerical simulations, some useful results would be addressed for the performance of NMPV micropumps. First, Reynolds number confirmed by steady analysis should be greater than 10 (Re > 10) for the NMPV pumps to be more effective. Second, an optimal Strouhal number with maximum net volume flow rate is found at St = 0.013 for the unsteady flow condition. In addition, the relation between the driving pressure amplitude and net volume flow rate with a linear behavior found was helpful to the performance of the micropump system. According to these findings, it was easy for users to operate and design of NMPV micropumps.

scholarly journals The Long Bubbles Penetration through Viscoelastic Fluids with Shear-Thinning Viscosity in a Curved Tube

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Ching-Chuan Chang
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Viscoelastic Fluids ◽  
Weissenberg Number ◽  
Fluid Viscosity ◽  
Gas Flow Rate ◽  
Difference Variable ◽  
Curved Tube ◽  
Number Increase ◽  
The Difference

The purpose of this research is to investigate the behavior of a long bubbles penetrating through viscoelastic fluids in a curved tube. The injection gas flow is controlled by a mass flow controller (MFC). The results of the experiments show that the bubbles width approaches constant value at the location six-diameter upstream from the bubbles front. A difference variable is introduced at the six-diameter location to show the shifting deviation of the bubbles in the curved tube. It is shown that, with the same fluid viscosity and the curved angle, the difference is higher when the gas flow rate is higher. Also, the difference increases proportionally when the capillary number and the Weissenberg number increase.

scholarly journals Study of Four Passive Second Skin Façade Configurations as a Natural Ventilation System During Winter and Summer

2021 ◽  
Vol 28 (1) ◽  
pp. 94-105
Author(s):  
Youssef Hamidi ◽  
Mustapha Malha ◽  
Abdellah Bah
Keyword(s):  
Flow Rate ◽  
Fossil Fuels ◽  
Natural Ventilation ◽  
Climate Models ◽  
Energy Savings ◽  
Volume Flow Rate ◽  
Ventilation System ◽  
Volume Flow ◽  
Design Strategies ◽  
The Difference

The fight against climate change is a significant challenge, resulting mainly from the linear and extensive exploitation of natural resources, particularly fossil fuels. Its impacts are now recognized. The current climate models are neither sustainable nor ecological in economic and social terms, especially as we live in a century marked by galloping demography and urbanization. Researchers worldwide have paid great attention to passive solar design strategies such as double skin or Second Skin Façade.  From this point, the present work aims to contribute to a better understanding of the feasibility of using a passive façade as a useful technology for natural ventilation to achieve potential energy savings and improve thermal comfort and indoor air quality. For this purpose, a parametric study was conducted for a room with four different southern facade configurations in six Moroccan climatic zones; the difference between each lies in the vent's position in the entrance and exit. This process was done by using COMSOL Multiphysics software. Velocity and volume flow rate fields were analyzed. The proposed configurations provided an average volume flow rate between 200 m3/h and 400 m3/h for a surface of 1 m2 of southern façade with an air vent area of 0.1mx0.2m.

scholarly journals Saliva secretion difference before and after rinsing with baking soda on menopause women

2007 ◽  
Vol 19 (1) ◽  
Author(s):  
Dewi Anggraeni ◽  
Sri Tjahajawati ◽  
Rosiliwati Wihardja
Keyword(s):  
Statistical Analysis ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Survey Method ◽  
Average Volume ◽  
Saliva Secretion ◽  
Significant Difference ◽  
Before And After ◽  
The Difference

Menopause women can experience a decrease in saliva secretion (decrease). To understand the clear picture about saliva secretion, the volume, flow rate, pH and viscosity were then measured. The aim of this research was to obtain a picture about the difference of saliva secretion before and after rinsing with baking soda on menopause women. The type of the research used was a laboratory quasi-experiment with comparative descriptive form. The technique used in this research is the survey method, and samples were taken using the multistage cluster random sampling method, and t-student statistical analysis. This research was conducted with the saliva collected with spitting method on 45 menopause women. The results show that the average volume, flow rate, pH and viscosity before rinsing with baking soda was 1.79 ml, 0.18 ml/minute, 7.40 and 0.81 mm2/second. The average volume, flow rate, pH and viscosity after rinsing with baking soda were 2.66 ml; 0.27 ml/minute; 8.67 and 0.78 mm2/second. Statistical analysis t-student on α = 0.05 shows volume changes, flow rate, pH and saliva viscosity before and after rinsing with baking soda was 0.873; 0.086; 1.273 and 0.037 respectively. The conclusion shows a significant difference between saliva secretion before and after rinsing with baking soda, and saliva secretion after rinsing with baking soda on menopause women.

scholarly journals Oscillatory Flow Rate Measurement of Ideal Gases from a Velocity at a Point in a Pipeline Using Micro Flow Sensor

2000 ◽  
Vol 36 (7) ◽  
pp. 549-554
Author(s):  
Kenji KAWASHIMA ◽  
Tatsuya FUNAKI ◽  
Toshinori FUJITA ◽  
Toshiharu KAGAWA ◽  
Kazumitsu NUKUI
Keyword(s):  
Flow Rate ◽  
Oscillatory Flow ◽  
Flow Sensor ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
Ideal Gases ◽  
Micro Flow

scholarly journals A microcantilever-based gas flow sensor for flow rate and direction detection

2008 ◽  
Author(s):  
Yu-Hsiang Wang ◽  
Tzu-Han Hsueh ◽  
Rong-Hua Ma ◽  
Chia-Yen Lee ◽  
Lung-Ming Fu ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Flow Sensor ◽  
Direction Detection

Mass Flow Rate Measurements in Nitrogen Flows

2006 ◽  
Author(s):  
Pierre Perrier ◽  
Timothe´e Ewart ◽  
J. Gilbert Me´olans ◽  
Irina A. Graur
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Flow ◽  
Steady Flows ◽  
Transitional Regime ◽  
Slip Regime ◽  
Mass Flow Rates ◽  
Micro Flow ◽  
Nitrogen Flows

The main objective of this experimental investigation on the gas flow slip regime is to measure the mass flow rate in isothermal steady flows through cylindrical micro tubes. Two technical procedures devoted to mass flow rate measurements are compared, and the measured values are also compared with the results yielded by different approximated analytical solution of the gas dynamics continuum equations. Satisfactory results are obtained and the way is clearly open to measuring mass flow rates for higher Knudsen numbers, over all the micro flow transitional regime.

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