The effects of torsion, aspect ratio and curvature on the flow in a helical pipe of rectangular cross- section are studied by introducing a non-orthogonal helical coordinate system. Spectral method is applied as main tool for numerical approach where Chebyshev polynomial is used. The numerical calculations are obtained by the iterative method. The calculations are carried out for 0⤠δ â¤0.02, 1⤠λ ⤠2.85, 1⤠γ â¤2.4, at Dn = 50 & 100 respectively, where d is the non-dimensional curvature, l the torsion parameter, g the aspect ratio and Dn the pressure driven parameter (Dean number).DOI: http://dx.doi.org/10.3329/jname.v4i2.991 Journal of Naval Architecture and Marine Engineering Vol.4(2) 2007 p.99-110
The response of a fully developed pipe flow to wall mounted roughness elements of rectangular cross section was investigated experimentally using a probe with a single hot-wire. Four heights of rectangular, ring-type elements were installed rigidly in a 63.5-mm diameter, smooth-walled, circular pipe in which air was flowing at a Reynolds number of 50,000. After passing over the roughness element, the flow recovery occurred in three stages. The three flow regions are delineated, and the velocity profiles for each are correlated.
The paper investigates the elastic equilibrium of a long bar of rectangular cross-section in those cases where the problem may be treated as one of two dimensions, namely:— (
a
.) When the strain being in the plane of
xy
, the elastic solid extends indefinitely in the direction of the applied stresses over the bounding planes
y
= ±
b
,
x
= ±
a
being the same for any two sections parallel to the plane of
xy
. We then have a strictly two-dimensional strain.
AbstractIn this paper the spatial and temporal evolution of pulsed plasma sheath around a micropatterned surface is investigated using two-dimensional fluid model. The simulation region is considered as a micro-sized tip with rectangular cross section. The effects of rise time on electric field, ion density distributions, and dose of ions impacting the target are studied. It is shown that the plasma sheath has a balloon-like behavior in the early time stages.
SummaryThe velocity and pressure distributions in a flow generated by a thick air jet that throttles a confined airstream have been studied analytically and experimentally. Velocity and pressure measurements were made in a duct with a rectangular cross section of 102 mm height and 19 mm depth, through which air flowed at velocities ranging from 65 to 80 m/s. The airstream was throttled by a thick air jet having velocities ranging from 130 to 150 m/s that entered the mainstream at angles ranging from 60° to 135°. The jet-mainstream contour was found to be elliptical and agreement within six per cent was obtained between the theoretically and experimentally determined maximum height of the contour. Jet spreading was found to be linear. The theory permits determination of the velocity profile in the jet and gives velocities that deviate less than ten per cent from values obtained experimentally.
Velocity measurements are reported for steady and unsteady flow in a rectangular cross-section Y-branch of high aspect ratio. Good agreement is found between the experimental results and two-dimensional calculations. Emphasis is placed on flow velocities near and parallel to the outer wall inasmuch as their gradients are proportional to wall shearing stress which may be of influence in atherogenesis. Large variation in flow velocities and hence shearing stress are found in the immediate vicinity of the corner. The results in this region could support theories which propose either high or low shearing stress as an important consideration in the etiology of arteriosclerosis.
Rectangular microchannel is the most popular shape to be widely used in Microelectromechanical devices. However, analytical solutions of flow in this shape of microchannels are seldom reported because of its two dimensional problem. Furthermore, microflows in microchannels are more difficult to describe. In this paper, we addressed analytically the problem of laminar electrokinetic slip flow in microchannels with rectangular cross-section subjected to a time-dependent pressure gradient and a time-dependent electric field. The analytical solution has been determined based on the Debye-Hu¨ckel approximation and its solution is useful to precisely control microflow with slip in rectangular cross-section microchannels.
Flow through a helical pipe with rectangular cross-section