Local Pipe Friction Factor of Compressible Laminar or Turbulent Flow in Micro-Tubes

Murakami, Shintaro; Asako, Yutaka

doi:10.1299/kikaib.77.1429

Cited by 3 publications

(6 citation statements)

References 19 publications

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“…For the smallest tube of d ¼ 85.6 mm, the transition to turbulent flow delays and the friction factors in the range of 2000 < Re < 8000 are lower than the values predicted from the Blasius formula and the friction factors in the range of 8000 < Re are higher than the values predicted from the Blasius formula. The average friction factors for 308.4 mm tube agree well with the numerical results obtained by Murakami and Asako 7 in the range of Re 45000 and the average friction factor is 20% higher than the value predicted from the Blasius formula around Re ¼ 10,000. The average friction factors for 920.1 mm tube agree well with the numerical results obtained by Murakami and Asako 7 in the range of Re 412,000 and the average friction factor is 20% higher than the value predicted from the Blasius formula around Re ¼ 20,000.…”

Section: Introductionsupporting

confidence: 87%

“…The average friction factors for 308.4 mm tube agree well with the numerical results obtained by Murakami and Asako 7 in the range of Re 45000 and the average friction factor is 20% higher than the value predicted from the Blasius formula around Re ¼ 10,000. The average friction factors for 920.1 mm tube agree well with the numerical results obtained by Murakami and Asako 7 in the range of Re 412,000 and the average friction factor is 20% higher than the value predicted from the Blasius formula around Re ¼ 20,000.…”

Section: Introductionsupporting

confidence: 87%

“…The numerical results obtained by Murakami and Asako 7 are also plotted by a dashed line in Figure 11. The experimental results are 12-20% higher than the values predicted from the Blasius formula.…”

Section: Friction Factormentioning

confidence: 98%

“…Those values coincide with the Blasius formula and also the numerical results by Murakami and Asako. 7 The quasi-local friction factor is the average friction factor between the pressure tap holes. There is no discrepancy between the quasi-local friction factor and the local friction factor.…”

Section: Friction Factormentioning

confidence: 99%

“…Asako et al 5,6 investigated laminar gaseous flow in a circular tube and found that the Fanning friction factor is a function of Reynolds and Mach numbers. Recently, Murakami and Asako 7 numerically obtained the friction factor for turbulent gaseous flow in a micro-tube and found that the Fanning friction factor based on the friction loss almost coincides with Blasius formula and it is not a function of Mach number.…”

Section: Introductionmentioning

confidence: 97%

See 4 more Smart Citations

Measurement of quasi-local friction factor of gas flow in a micro-tube

Kawashima

Asako

2015

Proceedings of the Institution of Mechanical Engineers, Part C:

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This paper presents experimental results on the friction factor of gaseous flow in a PEEK micro-tube with arithmetic mean roughness of 0.2 mm (relative surface roughness of 0.04%). The experiments were performed for nitrogen gas flow through the micro-tube with 514.4 mm in diameter and 50 mm in length. Three pressure tap holes were drilled on the PEEK micro-tube wall at intervals of 5 mm and the local pressures were measured. The quasi-local friction factor is obtained from the measured pressure differences. The experiments were conducted in the turbulent flow region. The quasi-local friction factor obtained from the present study is compared with those in the available literature and also numerical results. The quasi-local friction factor obtained is 12-20% higher than the value predicted from the Blasius formula.

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Section: Introductionsupporting

confidence: 87%

Section: Introductionsupporting

confidence: 87%

Section: Friction Factormentioning

confidence: 98%

Section: Friction Factormentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

See 3 more Smart Citations

Measurement of quasi-local friction factor of gas flow in a micro-tube

Kawashima

Asako

2015

Proceedings of the Institution of Mechanical Engineers, Part C:

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Data reduction of friction factor of compressible flow in micro-channels

Kawashima

Asako

2014

International Journal of Heat and Mass Transfer

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Pressure loss prediction of gaseous flow in a conduit-system of microchannel heat exchanger

Murakami

Toyoda

Asako³

2020

Transactions of the JSME (In Japanese)

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Three methods for predicting pressure loss of gaseous flow in a conduit-system of microchannel heat exchanger are proposed and discussed. In the experiment, the heat transfer plate which is the core of the heat exchanger has 34 rectangular microchannels. The microchannels are 330 m in width, 200 m in depth and 20 mm in length. The working fluid is air at room temperature, which is compressed to flow in the heat exchanger and flows out to atmospheric surroundings. The static pressures were measured at the inlet and outlet of the conduit-system. The conduit-system, namely, the heat exchanger and the piping system, includes several factors of pressure loss such as pipe friction, sudden expansion or contraction at the joints of piping system, besides the conventional loss at the heat exchanger core. These additional losses cannot be ignored because the hydraulic diameters of piping system tend to be small for microchannel heat exchangers. The prediction methods are formulated with the assumption that the pressure loss coefficients (such as pipe friction factor) have the same value of those of incompressible flow. One of the methods is simply formulated assuming isothermal flow and constant densities in each conduit-element, and another one is based on one-dimensional adiabatic flow theory. These two methods adopted pressure loss correlation of incompressible flow as approximation. The third method adopted modified pressure loss correlation where the essence of pressure loss is considered as internal heat generation by dissipation, and total pressure loss is calculated based on isobaric curves on h-s chart using entropy increase by the heat generation. When the measured outlet pressure is used as initial value of prediction, the third method gives the best prediction of static pressure difference between the inlet and outlet of the conduit-system within 3.9% difference from the experiment in the range of 371-1460 of channel Reynolds number.

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Local Pipe Friction Factor of Compressible Laminar or Turbulent Flow in Micro-Tubes

Cited by 3 publications

References 19 publications

Measurement of quasi-local friction factor of gas flow in a micro-tube

Measurement of quasi-local friction factor of gas flow in a micro-tube

Data reduction of friction factor of compressible flow in micro-channels

Pressure loss prediction of gaseous flow in a conduit-system of microchannel heat exchanger

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