scholarly journals 2D flow model for calculating effective area of piston-cylinder units

ACTA IMEKO ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 319
Author(s):  
W. Sabuga ◽  
A. S. Hashad ◽  
S. Ehlers
Keyword(s):  
Flow Model ◽  
Effective Area ◽  
Dimensional Properties ◽  
Piston Cylinder ◽  
Gauge Pressure ◽  
2D Flow ◽  
Uncertainty Contribution ◽  
2D Model

A 2D flow model is described for calculation of the effective area (<em>A</em>) of pressure-measuring piston-cylinder units (PCU) based on their dimensional properties. With the 2D model, the uncertainty contribution associated with PCU's axial non-symmetry can be eliminated and the uncertainty of <em>A</em> can be reduced. The 2D model is applied to several primary PCUs operated in absolute and gauge pressure modes with different pressure-transmitting media. The benefit of the 2D model in dependence on PCU's geometrical perfectness is discussed.

Hydraulic analysis of a meander on the Danube River using a 2D flow model

2020 ◽  
Vol 192 (2) ◽  
Author(s):  
Zoltan Horvat ◽  
Mirjana Horvat ◽  
Fruzsina Majer ◽  
Dániel Koch
Keyword(s):  
Flow Model ◽  
Danube River ◽  
Hydraulic Analysis ◽  
The Danube River ◽  
2D Flow

Evaluation of effective area of air piston gauge with limitations in piston-cylinder dimension measurements

Metrologia ◽  
2021 ◽  
Author(s):  
Vikas Narayan Thakur ◽  
Felix Sharipov ◽  
Yuanchao Yang ◽  
Sandeep Kumar ◽  
Jokhan Ram ◽  
...  
Keyword(s):  
Effective Area ◽  
Piston Cylinder ◽  
Piston Gauge

scholarly journals A Hybrid 1D/2D Flow Model of Non-Newtonian Fluids in Single Cavity Die

2011 ◽  
Vol 77 (780) ◽  
pp. 1609-1619
Author(s):  
Hiroshi KINUGAWA ◽  
Takeaki TSUDA ◽  
Koichi NAKANO ◽  
Harumichi KYOTO
Keyword(s):  
Flow Model ◽  
Newtonian Fluids ◽  
2D Flow ◽  
Single Cavity

A Novel Thermal Model for the Piston/Cylinder Interface of Piston Machines

2009 ◽  
Author(s):  
Matteo Pelosi ◽  
Monika Ivantysynova
Keyword(s):  
Temperature Field ◽  
Energy Dissipation ◽  
Film Thickness ◽  
Elastic Deformation ◽  
Flow Model ◽  
Piston Cylinder ◽  
Gap Flow ◽  
First Time ◽  
Fully Coupled

The lubricating gaps of piston machines represent the main source of energy dissipation. The lubricating gap in these machines has to fulfill a sealing and bearing function. Therefore the prediction of the gap flow, the load carrying ability and the energy dissipation is necessary. The paper discusses a novel fully coupled model for the determination of piston/cylinder gap behavior considering the contribution of solid parts temperature induced strain. In particular, the non-isothermal gap flow model considers the squeeze film effect due to the micro-motion of the moveable parts and simultaneously the change of fluid film thickness due to the elastic deformation of the solid bodies caused by the fluid pressure field and the parts temperature field. The determination of the temperature field inside the parts, by means of detailed finite volume models, allows for the first time to accurately predict solid parts thermal expansion, which is directly affecting the gap film thickness. Therefore, the novelty of the developed fully coupled fluid-structure-thermal interaction model is the integration of a finite element solver for the determination of surface thermo-elastic deformation in a dynamic non-isothermal fluid flow model. This will allow for the first time to solve the thermo-elastohydrodynamic lubrication problem under changing load conditions, considering the impact of several different physical phenomena.

scholarly journals EVALUATION ON THE CONSISTENCY OF CALIBRATION RESULTS BETWEEN REFERENCE STANDARDS OF PNEUMATIC PRESSURE BALANCE BASED ON NON-FULL RANGE CALIBRATION

2019 ◽  
Vol 21 (3) ◽  
pp. 203
Author(s):  
Adindra Vickar Ega ◽  
R.Rudi Anggoro Samodro
Keyword(s):  
High Pressure ◽  
Pressure Range ◽  
Full Range ◽  
Effective Area ◽  
National Metrology Institute ◽  
Pressure Balance ◽  
Pneumatic Pressure ◽  
Piston Cylinder ◽  
Normalized Error ◽  
High Pressure Range

<p>To provide calibration services for pressure measuring devices, SNSU-BSN has several piston-cylinder standard that may traceable to different National Metrology Institute (NMIs). Non-full range calibration of pressure balance has been performed to evaluate the consistency of calibration results between those standard, especially for establishing self-traceability in the future. In this research, a piston-cylinder unit S/N 1926 with medium pressure range of 1750 kPa, was calibrated with low pressure range S/N 978 of 350 kPa and high pressure range S/N 1054 of 7000 kPa. The calibration was performed with cross-float method to evaluate the effective area of piston-cylinder at null pressure and reference temperature of 20⁰C (<em>A<sub>0,20</sub></em>) and distortion coefficient (λ) as the 1926 main parameters. The obtained value, respectively are (1.961 166 × 10<sup>-4</sup> ± 4.4 × 10<sup>-9</sup>) m<sup>2 </sup>and (-1.67 × 10<sup>-12</sup> ± 9.4 × 10<sup>-13</sup>) Pa<sup>-1 </sup>from 978 and (1.961166 × 10<sup>-4</sup> ± 5.1 × 10<sup>-9</sup>) m<sup>2</sup> and (-1.58 × 10<sup>-12</sup> ± 8.4 × 10<sup>-13</sup>) Pa<sup>-1 </sup>from 1054. The result of 1926 from both methods shows good conformity with Normalized Error (En) of 0.0007 and 0.069, respectively. Linearity of effective area changes to the pressure is very consistent in both low and high pressure range. Validation results by using PTB-Germany results, shows the relative different for <em>A<sub>0</sub></em> and <em>λ</em> obtained are less than 0,1 × 10<sup>-6</sup> and 6%,respectively. Therefore, the pneumatic pressure balance of SNSU-BSN is traceable, consistent with each other and capable for disseminating the pressure unit along all primary pressure standard owned with high agreement compared to those of other advance NMIs.</p>

Verification of Gas Flow Traceability from 0.1 sccm to 1 sccm Using a Piston Gauge

NCSLI Measure ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 10-16
Author(s):  
Michael Bair
Keyword(s):  
Laminar Flow ◽  
Gas Flow ◽  
Vertical Displacement ◽  
Pressure Control ◽  
Effective Area ◽  
Flow Measurements ◽  
Piston Cylinder ◽  
Measurement Assurance ◽  
Piston Gauge ◽  
Means Of Measurement

Fluke Calibration is accredited for gas flow measurements in the range of 0.1 sccm to 6000 slm in nitrogen and air. Traceability is maintained directly through a gravimetric f low standard but only recently from 1 sccm to 10 sccm. The traceability of flow in the range of 0.1 sccm to 1 sccm is based on extrapolation of the use of laminar flow elements (LFE) below 1 sccm. This part of the range has never been completely verified through interlaboratory comparisons, proficiency testing or other means of measurement assurance. In an internal document from DH Instruments in the early 1990s it was suggested that a piston gauge might improve traceability for very low gas flows. In order to prove out traceability in this range an attempt was made to use a piston gauge using a piston-cylinder size of 35 mm diameter as a reference. One reason for choosing a piston gauge as a reference is its pressure control. This is crucial when measuring gas flow through a LFE in this design and range. In addition, the effective area is known to within 0.001 %, leaving the vertical displacement of the piston to dominate the uncertainty of the dimensional part of the flow test. This was a challenge because the measurements required absolute mode and the internal piston position sensor supplied with the piston gauge did not have sufficient precision. This paper describes the theory and design of the gas flow measurement system, the current results, and improvements desired or suggested. Two different designs are discussed, one with a single piston gauge as a reference and one with two piston gauges measuring flow on either side of the laminar flow element. Note: sccm (standard cubic centimeters per minute) is an industry accepted alternative to kg/s [1]. It is used out of convenience to normalize flow rates of gases with significant differences in density.

Numerical Simulation of 2D Hydraulic Jump Flow in a Vertical Plane

2012 ◽  
Vol 482-484 ◽  
pp. 16-20
Author(s):  
Wen Li Wei ◽  
X.J Zhao ◽  
Y. L Liu
Keyword(s):  
Free Surface ◽  
Hydraulic Jump ◽  
Flow Model ◽  
Vertical Plane ◽  
Surface Profile ◽  
Governing Equations ◽  
Proposed Model ◽  
2D Flow ◽  
Time Changes ◽  
Volume Method

This paper was concerned with a vertical two-dimensional (2D) flow model with free surface. The water governing equations were discretized with finite difference method. The function of volume method was employed to track the moving free surface. The model was used to predict the characteristics of hydraulic jump flow in a 2D vertical plane. The surface profile and time averaged velocity were calculated, which shows the proposed model can be capable of capturing sharp water and gas interface configuration as time changes.

scholarly journals Rarefied gas flow in pressure and vacuum measurements

ACTA IMEKO ◽  
2014 ◽  
Vol 3 (2) ◽  
pp. 60 ◽  
Author(s):  
Jeerasak Pitakarnnop
Keyword(s):  
Gas Flow ◽  
Rarefied Gas ◽  
Slip Flow ◽  
Effective Area ◽  
Low Flow ◽  
Vacuum System ◽  
Rarefied Gas Flow ◽  
Pressure Balance ◽  
Piston Cylinder ◽  
Flow Leak

Flows of a gas through the piston-cylinder gap of a gas-operated pressure balance and in a general vacuum system have one aspect in common, namely that the gas is rarefied due, respectively, to the small dimensions and the low pressure. The flows in both systems could be characterised as being in either slip-flow or transition regimes. Therefore, fundamental research of flow in these regimes is useful for both pressure and vacuum metrology, especially for the gas-operated pressure balance where a continuum viscous flow model is widely used for determining the effective area of the pressure balance. The consideration of gas flow using the most suitable assumption would improve the accuracy of such a calculation. Moreover, knowledge about rarefied gas flow will enable gas behaviour in vacuum and low-flow leak detection systems to be predicted. This paper provides useful information about rarefied gas flow in both slip-flow and transition regimes.

scholarly journals Establishment of air piston gauge as primary pressure standard at CSIR-National Physical Laboratory INDIA

ACTA IMEKO ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 329
Author(s):  
Vikas N. Thakur ◽  
Sanjay Yadav ◽  
Ashok Kumar
Keyword(s):  
Primary Standard ◽  
Effective Area ◽  
National Physical Laboratory ◽  
Area Measurement ◽  
Internal Diameter ◽  
Piston Cylinder ◽  
Piston Gauge ◽  
Si Units ◽  
Physical Laboratory ◽  
Pressure Standard

The air piston gauge (APG) was established at CSIR-National Physical Laboratory, India (NPLI) since 2000. Later the same piston- cylinder(p-c) assembly was calibrated in NIST USA; however, it was never published for metrology communities. As per international protocol, the establishment of the APG as a primary standard, the effective area of p-c assembly, and masses must be directly traceable to SI units. The first time we have calculated the effective area and associated uncertainty of p-c assembly using dimension and mass metrology, traceability to the SI units, i.e., meter and kilogram. To realize the APG as primary pressure standards, we have calculated the effective area of p-c assembly of APG directly from dimension metrology, which is further supported by various other methods. The effective area values obtained in the pressure range of 6.5 – 360 kPa lie in the range of 3.356729 – 3.357248 cm² due to uncertainty limitation in the measurement of dimension of internal diameter of cylinder. The expected values of the effective area which are also measured from cross-float technique against ultrasonic interferometer manometer (UIM), primary pressure standards. The accuracy in effective area measurement is possible only when the resolution in the internal radius of the cylinder should at least be up to 5th decimal order and the uncertainty is 80 nm. The expanded uncertainty was measured nearly 11 ppm at <em>k</em> = 2 by considering the uncertainty in internal radii of cylinder and radii of piston around 80 nm.

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