Experimental Investigations on Friction Factors of Gaseous Flow Through a Micro-Tube With Smooth Surface

2017 ◽  
Author(s):  
Takayuki Shigeishi ◽  
Chungpyo Hong ◽  
Yutaka Asako
Keyword(s):  
Friction Factor ◽  
Smooth Surface ◽  
Gas Flow ◽  
Experimental Investigations ◽  
Adiabatic Wall ◽  
Choked Flow ◽  
Friction Factors ◽  
Wide Range ◽  
Flow Through ◽  
Local Pressures

The purpose of the present study is to experimentally investigate flow characteristics on semi-local friction factors of nitrogen gas flow through a micro-tube with a smooth surface. The experiments were performed using a glass micro-tube with 266 μm in diameter and 120 mm in length. Three static pressure holes are drilled on the wall near the micro-tube outlet at intervals of 5 mm, and the local pressures were measured with the outlet discharged into the atmosphere. The local values of Mach number, temperature and friction factor were obtained from the measured local pressures. The result in the wide range of Reynolds number was also obtained, including the choked flow. Darcy friction factor and Fanning friction factor obtained under the assumptions of both a Fanno flow (adiabatic wall) and an Isothermal flow were compared with empirical correlations in the literature and numerical results.

Semi Local Friction Factor of Gas Flow Through a Micro-Tube

2017 ◽  
Author(s):  
Kenshi Maeda ◽  
Chungpyo Hong ◽  
Yutaka Asako
Keyword(s):  
Friction Factor ◽  
High Speed ◽  
Gas Flow ◽  
Electrical Discharge Machining ◽  
Tube Wall ◽  
Gas Temperature ◽  
Local Pressure ◽  
Adiabatic Wall ◽  
Friction Factors ◽  
Flow Through

Flow characteristics of laminar gas flow through a micro-tube were experimentally studied on friction factors in this paper. The experiments were performed for nitrogen flow through a stainless steel micro-tube with 123.87 μm in diameter and 50mm in length. Two static pressure tap holes were fabricated on the micro-tube wall at intervals of 5mm with electrical discharge machining. The local pressure was measured to determine the local values of Mach number, temperature and friction factor. Both the Fanning and the Darcy friction factors were obtained under the assumption of a Fanno flow (adiabatic wall) since the external micro-tube wall was covered with the foamed polystyrene. The effects of temperature decrease on friction factors were investigated because the gas temperature steeply decreases near the outlet due to energy conversion from thermal energy into kinetic energy in a high speed gas flow. The obtained friction factors were compared with those in the available literature and also with numerical results.

Estimation of Leak Flow Rates Through Narrow Cracks

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Chungpyo Hong ◽  
Yutaka Asako ◽  
Jae-Heon Lee
Keyword(s):  
Friction Factor ◽  
Gas Flow ◽  
Slip Flow ◽  
Nonlinear Ordinary Differential Equation ◽  
Opening Displacement ◽  
Flow Rates ◽  
Choked Flow ◽  
Runge Kutta Method ◽  
Wide Range ◽  
Leak Before Break

The estimation of the gaseous leak flow rates through a narrow crack is important for a leak-before-break analysis as a method of nondestructive testing. Therefore, the methodology to estimate the gaseous leak flow rates in a narrow crack for a wide range of flow conditions, from no-slip to slip flow and from unchoked to choked flow, by using f⋅Re (the product of friction factor and Reynolds number) correlations obtained for a microchannel, was developed and presented. The correlations applied here were proposed by the previous study (Hong, et al., 2007, “Friction Factor Correlations for Gas Flow in Slip Flow Regime,” ASME J. Fluids Eng., 129, pp. 1268–1276). The detail of the calculation procedure was appropriately documented. The fourth-order Runge–Kutta method was employed to integrate the nonlinear ordinary differential equation for the pressure, and the regular-Falsi method was employed to find the inlet Mach number. An idealized crack, whose opening displacement ranges from 2 μm to 50 μm, with the crack aspect ratio of 200, 1000, and 2000, was chosen for sample estimation. The present results were compared with both numerical simulations and available experimental measurements. The results were in excellent agreement. Therefore, the gaseous leak flow rates can be correctly predicted by using the proposed methodology.

Measurement of Semi-Local Friction Factor of Gas Flow in Micro-Tube

2013 ◽  
Author(s):  
D. Kawashima ◽  
Y. Asako
Keyword(s):  
Surface Roughness ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Gas Flow ◽  
Flow Region ◽  
Nitrogen Gas ◽  
Gaseous Flow ◽  
Flow Through ◽  
Local Pressures ◽  
Measured Pressure

This paper presents experimental results on friction factor of gaseous flow in a PEEK micro-tube with relative surface roughness of 0.04 %. The experiments were performed for nitrogen gas flow through the micro-tube with 514.4 μm in diameter and 50 mm in length. Three pressure taps holes with 5 mm interval were drilled and the local pressures were measured. Friction factor is obtained from the measured pressure differences. The experiments were conducted for turbulent flow region. The friction factor obtained by the present study are compared with those in available literature and also numerical results. The friction factor obtained is slightly higher than the value of Blasius formula.

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

2015 ◽  
Vol 230 (5) ◽  
pp. 782-792 ◽  
Author(s):  
D Kawashima ◽  
Y Asako
Keyword(s):  
Friction Factor ◽  
Gas Flow ◽  
Tube Wall ◽  
Flow Region ◽  
Arithmetic Mean ◽  
Nitrogen Gas ◽  
Gaseous Flow ◽  
Flow Through ◽  
Local Pressures ◽  
Measured Pressure

This paper presents experimental results on the friction factor of gaseous flow in a PEEK micro-tube with arithmetic mean roughness of 0.2 µm (relative surface roughness of 0.04%). The experiments were performed for nitrogen gas flow through the micro-tube with 514.4 µm 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.

Experimental Investigations of Turbulent Gas Flow in a Micro-Channel

2011 ◽  
Author(s):  
Shinichi Matsushita ◽  
Chungpyo Hong ◽  
Yutaka Asako ◽  
Ichiro Ueno
Keyword(s):  
Mach Number ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Gas Flow ◽  
Experimental Investigations ◽  
Micro Channel ◽  
Pressure Transducers ◽  
Friction Factors ◽  
Turbulent Flow Regime ◽  
Turbulent Gas Flow

This paper presents experimental investigations on turbulent gas flow characteristics of nitrogen gas through a micro-channel. The micro-channels were etched into silicon wafers, capped with glass, and their hydraulic diameter is 147.76 micro meters. The micro-channel was designed with a main flow channel and seven side channels, which lead to the pressure transducers. The stagnation pressure was designated in such a way that the flow is in turbulent flow regime. The outlet of the channel faced to the atmosphere. The pressures of the main channel at seven locations were measured by gauge pressure transducers to determine local values of Mach number. And the pressure differences of each pressure ports were measured by differential pressure transducers to obtain the pressure losses precisely. The pressure distribution of turbulent gas flow through a micro-channel falls steeply and Mach number increases near the outlet with increasing the inlet pressure due to flow acceleration. Both Darcy friction factor and Fanning friction factor were obtained for turbulent flow. The result shows that the obtained both friction factors were evaluated as a function of Reynolds number on the Moody chart. The values of Darcy friction factors differ from Blasius correlation for turbulent flow regime due to the compressibility effects, however the values of Fanning friction factors coincide with Blasius correlation.

Experimental Investigations of Laminar, Transitional to Turbulent Gas Flow in Rib-Patterned Micro-Channels

2011 ◽  
Author(s):  
Chungpyo Hong ◽  
Toru Yamada ◽  
Yutaka Asako ◽  
Mohammad Faghri ◽  
Ichiro Ueno
Keyword(s):  
Mach Number ◽  
Friction Factor ◽  
Gas Flow ◽  
Flow Direction ◽  
Channel Length ◽  
Experimental Investigations ◽  
Patterned Surfaces ◽  
Micro Channels ◽  
Wide Range ◽  
Turbulent Gas Flow

The effects of rib-patterned surfaces on laminar, transitional to turbulent gas flow in micro-channels were experimentally investigated in the present study. The experiments were performed for two micro-channels having either smooth or rib-patterned surfaces. The micro-channels were etched into silicon wafers and capped with glass substrates. The micro-ribs were patterned on the microchannel surfaces and oriented perpendicular to the flow direction. The pressure was measured at seven locations along the channel length to determine local values of Mach number and friction factor for a wide range of flow regime from laminar to turbulent flow. The friction factors with the hydraulic diameter based on the rib-to-upper-wall height were compared with that for incompressible theory on Moody chart. The values of the product of friction factor and Reynolds number (f·Re) as a function of Mach number were also compared with those of smooth micro-channels and incompressible theory.

Experimental Investigations of Laminar, Transitional to Turbulent Gas Flow in a Micro-Channel

2010 ◽  
Author(s):  
Chungpyo Hong ◽  
Toru Yamada ◽  
Yutaka Asako ◽  
Mohammad Faghri ◽  
Koichi Suzuki ◽  
...  
Keyword(s):  
Mach Number ◽  
Flow Regime ◽  
Gas Flow ◽  
Flow Characteristics ◽  
Channel Length ◽  
Transitional Flow ◽  
Experimental Investigations ◽  
Compressibility Effect ◽  
Micro Channels ◽  
Wide Range

This paper presents experimental results on flow characteristics of laminar, transitional to turbulent gas flows through micro-channels. The experiments were performed for three micro-channels. The micro-channels were etched into silicon wafers, capped with glass, and their hydraulic diameter are 69.48, 99.36 and 147.76 μm. The pressure was measured at seven locations along the channel length to determine local values of Mach number and friction factor for a wide range of flow regime from laminar to turbulent flow. Flow characteristics in transitional flow regime to turbulence were obtained. The result shows that f·Re is a function of Mach number and higher than incompressible value due to the compressibility effect. The values of f·Re were compared with f·Re correlations in available literature.

Friction factors in the theory of bifurcating Poiseuille flow through annular ducts

1974 ◽  
Vol 66 (1) ◽  
pp. 189-207 ◽  
Author(s):  
D. D. Joseph ◽  
T. S. Chen
Keyword(s):  
Friction Factor ◽  
Poiseuille Flow ◽  
Bifurcation Theory ◽  
Frequency Change ◽  
Pipe Flows ◽  
Friction Factors ◽  
Flow Through ◽  
Number Curve ◽  
Time Periodic ◽  
Time Periodic Solution

The objective of this paper is to show how to formulate a bifurcation theory for pipe flows in terms of the friction factor. We compute the slope of the friction factor vs. Reynolds number curve and the frequency change for the time-periodic solution which bifurcates from Poiseuille flow through annular ducts.

412 Semi-local Friction Factors of Gas Flow through Micro-tubes

2015 ◽  
Vol 2015.68 (0) ◽  
pp. 151-152
Author(s):  
Goku Tanaka ◽  
Chugpyo Hong ◽  
Yutaka Asako
Keyword(s):  
Gas Flow ◽  
Friction Factors ◽  
Flow Through

scholarly journals Friction-Factor Data for Flat-Plate Tests of Smooth and Honeycomb Surfaces

1992 ◽  
Vol 114 (4) ◽  
pp. 722-729 ◽  
Author(s):  
T. W. Ha ◽  
Dara W. Childs
Keyword(s):  
Flat Plate ◽  
Friction Factor ◽  
Smooth Surface ◽  
Factor Model ◽  
Test Apparatus ◽  
Cell Width ◽  
Plate Test ◽  
Friction Factors ◽  
Line Flow ◽  
Factor Data

Friction-factors for honeycomb surfaces are measured with a flat plate tester. The flat plate test apparatus is described and a method is discussed for determining the friction-factor experimentally. The friction-factor model is developed for the flat plate test based on the Fanno Line Flow. The comparisons of the friction-factor are plotted for smooth surface and twelve-honeycomb surfaces with three-clearances, 6.9 bar to 17.9 bar range of inlet pressure, and 5,000 to 130,000 range of the Reynolds number. The optimum geometries for the maximum friction-factor are found as a function of cell width to cell depth and clearance to cell width ratios.

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