Experimental Study of Nonlinear Effects under Torsion of the Uniform Cylinder with Initially Circular Cross Section

2015 ◽  
Vol 243 ◽  
pp. 29-34
Author(s):  
V.P. Bachurikhin ◽  
I.E. Keller ◽  
A.F. Merzlyakov ◽  
M.A. Yurlov
Keyword(s):  
Experimental Study ◽  
Cross Section ◽  
Nonlinear Effect ◽  
Cylindrical Specimen ◽  
Axial Stress ◽  
Circular Cross Section ◽  
Nonlinear Effects ◽  
Fixed Length ◽  
Oscillatory Component

The results of experiments related to torsion of uniform cylindrical specimen at the fixed length between the specimens ends are presented in this paper. Axial stress has been found, initially stretching and then compressing the sample which has an oscillatory component with the period of one turn. Reasons of this nonlinear effect that are not described in the references are discussed here.

Equilibrium radial positions of neutrally buoyant spherical particles over the circular cross-section in Poiseuille flow

2017 ◽  
Vol 813 ◽  
pp. 750-767 ◽  
Author(s):  
Yusuke Morita ◽  
Tomoaki Itano ◽  
Masako Sugihara-Seki
Keyword(s):  
Experimental Study ◽  
Cross Section ◽  
Poiseuille Flow ◽  
Equilibrium Position ◽  
Probability Function ◽  
Circular Cross Section ◽  
Spherical Particles ◽  
Inertial Migration ◽  
Entry Length ◽  
Neutrally Buoyant

An experimental study of the inertial migration of neutrally buoyant spherical particles suspended in the Poiseuille flow through circular tubes has been conducted at Reynolds numbers $(Re)$ from 100 to 1100 for particle-to-tube diameter ratios of ${\sim}$0.1. The distributions of particles in the tube cross-section were measured at various distances from the tube inlet and the radial probability function of particles was calculated. At relatively high $Re$, the radial probability function was found to have two peaks, corresponding to the so-called Segre–Silberberg annulus and the inner annulus, the latter of which was first reported experimentally by Matas et al. (J. Fluid Mech. vol. 515, 2004, pp. 171–195) to represent accumulation of particles at smaller radial positions than the Segre–Silberberg annulus. They assumed that the inner annulus would be an equilibrium position of particles, where the resultant lateral force on the particles disappears, similar to the Segre–Silberberg annulus. The present experimental study showed that the fraction of particles observed on the Segre–Silberberg annulus increased and the fraction on the inner annulus decreased further downstream, accompanying an outward shift of the inner annulus towards the Segre–Silberberg annulus and a decrease in its width. These results suggested that if the tubes were long enough, the inner annulus would disappear such that all particles would be focused on the Segre–Silberberg annulus for $Re<1000$. At the cross-section nearest to the tube inlet, particles were absent in the peripheral region close to the tube wall including the expected Segre–Silberberg annulus position for $Re>700$. In addition, the entry length after which radial migration has fully developed was found to increase with increasing $Re$, in contrast to the conventional estimate. These results may be related to the developing flow in the tube entrance region where the radial force profile would be different from that of the fully developed Poiseuille flow and there may not be an equilibrium position corresponding to the Segre–Silberberg annulus.

Thermoelastic Stresses in Beams

1960 ◽  
Vol 27 (3) ◽  
pp. 465-473 ◽  
Author(s):  
E. S. Barrekette
Keyword(s):  
Cross Section ◽  
Axial Stress ◽  
Circular Cross Section ◽  
Successive Approximations ◽  
Method Of Successive Approximations ◽  
Materials Analysis ◽  
Linear Partial Differential Equations ◽  
Thermoelastic Stresses ◽  
Linear Integral ◽  
Homogeneous Linear

The behavior of elastic, free beams of arbitrary constant cross section under an arbitrary temperature distribution is investigated. An analytical method of successive approximations for the solution of linear partial differential equations is applied to the solution for thermoelastic stresses in such beams. The stresses are obtained in terms of series, the nth terms of which are of the form βnℒn(∂nT/∂nx) where β is the ratio of the maximum linear dimension of the cross section to the length of the beam, T is the temperature, x is the ratio of the axial co-ordinate to the length of the beam, and ℒn is a homogeneous linear integral differential operator in y and z only. When Poisson’s ratio is zero, the first term of the series for the normal axial stress is identical with the solution based on a strength-of-materials analysis, and the first term of the series for the axial displacement leaves plane sections plane. The leading terms of the series provide good approximations when the temperature can be expanded in a rapidly convergent power series and in long bars (β ≪ 1). The case of beams of constant circular cross section under temperatures varying only with the axial co-ordinate is examined and a numerical example is presented.

Experimental study of wall shear rates in the entry region of a curved tube

1979 ◽  
Vol 93 (3) ◽  
pp. 465-489 ◽  
Author(s):  
U. S. Choi ◽  
L. Talbot ◽  
I. Cornet
Keyword(s):  
Experimental Study ◽  
Cross Section ◽  
Circular Cross Section ◽  
Current Method ◽  
Limiting Current ◽  
Dean Number ◽  
Shear Rates ◽  
Rigid Tube ◽  
Curved Tube ◽  
Wall Shear

Local wall shear rates in steady flow in the entry region of a curved tube have been measured by the electrochemical limiting current method. A semi-circular rigid tube of circular cross-section with radius ratio 1/7 has been employed for a range of Dean number between 139 and 2868. The circumferential and axial distributions of the wall shear rates have been measured at 20° circumferential increments at five different sections of the entry region.

scholarly journals Experimental Study of Concrete-filled Steel Members with Circular Cross Section Subjected to Bending and Torsion.

1999 ◽  
pp. 85-97 ◽  
Author(s):  
Hiroshi NAKAI ◽  
Toshiyuki KITADA ◽  
Osamu YOSHIKAWA ◽  
Shuji MURAKAMI ◽  
Youichi SAKURAMOTO
Keyword(s):  
Experimental Study ◽  
Cross Section ◽  
Circular Cross Section ◽  
Steel Members

Experimental Study of Particle Deposition in Bends of Circular Cross Section

1987 ◽  
Vol 7 (3) ◽  
pp. 301-315 ◽  
Author(s):  
David Y. H. Pui ◽  
Francisco Romay-Novas ◽  
Benjamin Y. H. Liu
Keyword(s):  
Experimental Study ◽  
Cross Section ◽  
Particle Deposition ◽  
Circular Cross Section

An experimental study of pressure drop in helical pipes

1994 ◽  
Vol 444 (1921) ◽  
pp. 307-316 ◽  
Keyword(s):  
Experimental Study ◽  
Reynolds Number ◽  
Cross Section ◽  
Circular Cross Section ◽  
Square Root ◽  
Dean Number ◽  
Curvature Ratio ◽  
Pressure Drops ◽  
Newtonian Flows ◽  
Fanning Friction Factor

Pressure drops of fully-developed incompressible laminar newtonian flows in helical pipes of constant circular cross-section having a finite pitch are experimentally investigated. For the case of loosely coiled pipes of 0 < η/λ < 41.22, f Re ( f is the Fanning friction factor and Re is the Reynolds number) is found to be proportional to the square root of the flow Dean number, Dn = Re λ ½ . Here λ and η are the normalized curvature ratio and torsion which incorporate both the coil radius and its pitch. In all cases studied, the experimental results for f Re are in excellent agreement with the theoretical prediction of Liu & Masliyah.

Experimental study of the velocity of the flow of highly viscous Newtonian liquid in a curved rectangular duct

1986 ◽  
Vol 51 (1) ◽  
pp. 66-74
Author(s):  
Pavel Seichter
Keyword(s):  
Experimental Study ◽  
Stokes Equation ◽  
Cross Section ◽  
Circular Cross Section ◽  
Newtonian Liquid ◽  
Creeping Flow ◽  
Navier Stokes ◽  
Rectangular Duct ◽  
Navier Stokes Equation ◽  
Experimental Values

Thermistor anemometer measurements in a curved rectangular duct and a straight circular cross section tube permitted verification of the theoretical values of tangential velocities computed on the basis of the solution of the Navier-Stokes equation for the drag isothermal and creeping flow of a Newtonian liquid. From comparison of the theoretical and experimental values there follows that the achieved agreement is acceptable.

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