Methods of precisely estimating the jacket pressure coefficient of controlled-clearance piston-cylinders at pressures up to 1 GPa

Kajikawa, Hiroaki; Ide, Kazunori; Kobata, Tokihiko

doi:10.1088/0026-1394/48/5/016

Cited by 2 publications

(2 citation statements)

References 10 publications

(14 reference statements)

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“…and p m0 ≈ p m . Given the non-linearity of d j − p j , which were found both in literature [21,22,36] and in experiments [13,35], the relative change of A e due to distorted cylinder is calculated by by taking integral of d j dp j from the operational jacket pressure p j to the stall jacket pressure p j z . The jacket pressure distortion coefficient d j is the slope of the A e /A 0 − p j curve.…”

Section: The Expressions Of the Effective Areamentioning

confidence: 99%

“…However, viscosity does increase exponentially from low to high pressures [20]. In fact, p j − v 1/3 p were found to be non-linear near zero speed [21] and ∆p m − ∆p j were also found non-linear up to 1000 MPa [22]. The advantage of the H-W model is that A e can be determined without knowing exactly the cylinder's distortion, fluid properties (viscosity and density), or pressure distribution gradient in the piston-cylinder engagement region.…”

Section: Introductionmentioning

confidence: 99%

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Characteristic analysis of a controlled-clearance piston-cylinder assembly up to 1500 MPa using a finite element method

Liu,

Wang,

Zhang

et al. 2023

Metrologia

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We utilized numerical methods to analyze the characteristics of the piston-cylinder assembly of a controlled-clearance piston gauge. The piston gauge was able to measure liquid pressure from 100 MPa to 1500 MPa with relative expanded uncertainty of 0.02 % (k = 3). We established a finite element model to solve the stress and strain of the structural problem. The effective areas were calculated based on Dadson’s formula using the converged solutions of the clearance and the pressure distribution within the distorted piston-cylinder engagement gap that were iteratively determined by the finite element model and a fluid mechanics model with pressure-dependent fluid’s properties. Results were compared to the effective areas calculated by the modified Heydemann-Welch model based on experimental data, and the relative differences were less than 0.02%. We found sharp declines of the clearance and pressure distribution near the exit of the piston-cylinder engagement gap, which may lead to wearing during long-time operation at high pressures. Numerical results indicated non-linear relationship between jacket pressure and the cubic root of piston fall speed, which was traditionally considered as linear. The stall jacket pressure obtained by cubic (instead of linear) fitting extrapolation was found more close to the ones determined directly by the finite element model. Numerical results also found non-linear relationships among jacket pressure, measuring pressure, jacket pressure distortion coefficient.

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Section: The Expressions Of the Effective Areamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Characteristic analysis of a controlled-clearance piston-cylinder assembly up to 1500 MPa using a finite element method

Liu,

Wang,

Zhang

et al. 2023

Metrologia

View full text Add to dashboard Cite

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Numerical analysis of the accuracy of bivariate quantile distributions utilizing copulas compared to the GUM supplement 2 for oil pressure balance uncertainties

Ramnath

2017

Int. J. Metrol. Qual. Eng.

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Abstract. In the field of pressure metrology the effective area is A e = A 0 (1 + lP) where A 0 is the zero-pressure area and l is the distortion coefficient and the conventional practise is to construct univariate probability density functions (PDFs) for A 0 and l. As a result analytical generalized non-Gaussian bivariate joint PDFs has not featured prominently in pressure metrology. Recently extended lambda distribution based quantile functions have been successfully utilized for summarizing univariate arbitrary PDF distributions of gas pressure balances. Motivated by this development we investigate the feasibility and utility of extending and applying quantile functions to systems which naturally exhibit bivariate PDFs. Our approach is to utilize the GUM Supplement 1 methodology to solve and generate Monte Carlo based multivariate uncertainty data for an oil based pressure balance laboratory standard that is used to generate known high pressures, and which are in turn cross-floated against another pressure balance transfer standard in order to deduce the transfer standard's respective area. We then numerically analyse the uncertainty data by formulating and constructing an approximate bivariate quantile distribution that directly couples A 0 and l in order to compare and contrast its accuracy to an exact GUM Supplement 2 based uncertainty quantification analysis.

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Methods of precisely estimating the jacket pressure coefficient of controlled-clearance piston-cylinders at pressures up to 1 GPa

Cited by 2 publications

References 10 publications

Characteristic analysis of a controlled-clearance piston-cylinder assembly up to 1500 MPa using a finite element method

Characteristic analysis of a controlled-clearance piston-cylinder assembly up to 1500 MPa using a finite element method

Numerical analysis of the accuracy of bivariate quantile distributions utilizing copulas compared to the GUM supplement 2 for oil pressure balance uncertainties

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