4 edition of An investigation of transitional pipe flow using the photochromic tracer method found in the catalog.
An investigation of transitional pipe flow using the photochromic tracer method
Paul K. Zalzal
Thesis (M.A.Sc.)--University of Toronto, 1993.
|Series||Canadian theses = Thèses canadiennes|
|The Physical Object|
|Pagination||2 microfiches : negative.|
Numerical Method for Modeling Transient Flow in Distribution Systems Mehdi Salmanzadeh. Department of Mechanical Engineering Shoushtar Branch, Islamic Azad University, Shoushtar. Abstract: A transient is a temporary flow and pressure condition that occurs in a hydraulic system between an initial steady-state. In the proposed approach, active contours, snakes, are employed in a new curve-fitting method for tracer flow extraction in photochromic images. An algorithm implementing snakes is introduced to automate extraction. Utilizing correlation matching, the algorithm quickly locates and localizes all flow traces in the images.
The transitional flow in a pipe is important for delivery, but its characteristics remain to be explored. In this paper, the two-dimensional laser Doppler velocimetry (LDV) is used for the study, focusing on the attenuation characteristics of the axial velocity, the variation of the velocity gradient, the effect of the angle between the axis and the resultant velocity vector, and the. Pipe flow and friction pressure drop, head energy loss | Darcy formula From Bernoulli equation all other practical formulas are derived, with modifications due to energy losses and gains. As in real piping system, losses of energy are existing and energy is being added to or taken from the fluid (using pumps and turbines) these must be included.
The present article describes the results from a study of nonlinear mechanisms at work during the process of transition to turbulence in pipe flows. Using an accurate hybrid finite-difference code for the simulation of unsteady incompressible pipe flow, we have performed a direct numerical simulation designed to model experiments performed by. The standard model consistently over predicts turbulence at and downstream of the stenosis, which leads to premature recovery of the flow. While the transitional model often under-predicts the magnitude of the turbulence, the trends are well-described and the velocity field is superior to that predicted using the standard model.
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Two noninvasive measurement techniques are described for investigating transitional flow in a rigid straight tube. Photochromic trace recordings, representing fluid displacement profiles, were made within the core and at the leading and trailing edges of turbulent slugs generated by a disturbance at the tube inlet.
Consistent photochromic trace recordings were made possible through the Cited by: 4. A photochromic tracer method has been used to record pulsatile flow velocity profiles simultaneously at three axial locations along a flow channel.
Two major advantages of this multiple-trace method are that it enables velocity data to be acquired in an efficient non-invasive manner and that it provides a detailed description of the spatial Cited by: Intermittent turbulence in a pulsating pipe flow - Volume - RAFFAELLA TUZI, PAOLO BLONDEAUXCited by: Comparison of LES of Steady Transitional Flow in an Idealized Stenosed Axisymmetric Artery Model R.
Pulsatile flow through constricted tubes: an experimental investigation using photochromic tracer methods Owing to the length of the domain we have split the views of the first and second parts of the pipe.
The inset plot in Cited by: Turbulent and laminar pulsating flows in a straight smooth pipe are compared at identical frequencies and Reynolds numbers.
Most measurements were made at a mean Reynolds number ofbut the influence of Re was checked for Cited by: Direct numerical simulations (DNS) of stenotic flows under conditions of steady inlet flow were discussed in Part 1 of this study.
DNS of pulsatile flow through the 75% stenosed tube (by area) employed for the computations in Part 1 is examined here. Apparatus and Method 1.
Chemical Tracer Method As Fig. 1 shows, when ﬂuid with a ﬂow rate of Q 0 ﬂows in a pipe and a sample solution with a concentration of C in and with a ﬂow rate of Q in is injected at the injection point of the pipe, the mixed ﬂow rate at downstream of the pipe becomes (Q 0 þ Q in).
It is assumed that the. Pulsatile Flow Through Constricted Tubes: An Experimental Investigation Using Photochromic Tracer Methods,” Fully Developed Periodic Turbulent Pipe Flow, Part 1: Main Experimental Results and Comparisons With Predictions Method for the Calculation of Velocity, Rate of Flow and Viscous Drag in Arteries When the Pressure Gradient is.
Book Search tips Selecting this option will search all publications across the Scitation platform Selecting this option will search all Visualization of transitional pipe flow using the photochromic tracer method.
Zalzal, M. Ojha, C On the dynamical origin of asymptotic t 2 dispersion of a nondiffusive tracer in incompressible. Laminar flow, a correlation-based transitional version of Menter’s hybrid k ‐ ϵ ∕ k ‐ ω shear stress transport (SST) model and its “scale adaptive simulation” (SAS) variant were implemented in pulsatile simulations from which analyses of velocity profiles, wall shear stress, and turbulence intensity were conducted.
In general, the. The tracer method was first introduced to measure the actual flow of fluid in a vessel, and then to develop a suitable model to represent this flow. Such models are used to follow the flow of fluid in chemical reactors and other process units, in rivers and streams, and through soils and porous.
The photochromic flow visualization and measurement system. CCD, Charge-coupled device. The in vitro flow model or phantom and the filter were mounted on the motorized stage and positioned for the path of the laser beam.
This beam was focused by means of the convex lens to produce a dye trace within the flow field surrounding the filter. The transitional flow may be found in civil and industrial processes, and it is often treated as a turbu- lence.
Using this method to design the pipe system and to make the flow measurement will cause a remar- kable error, therefore, it is important to make a study of the flow of the transition area. Plastic Pipe Tracers are the smallest diameter product on the market and can be successfully inserted into pipes when nothing else fits.
Their unique construction gives unparalleled reliability and yet allows both line tracing AND the all important end tracing using the remarkable Sonde technology housed at the very tip of the Tracers.
The importance of edge states has indeed been highlighted for boundary layer and pipe flows, where their neighborhood is often visited before transition (Mellibovsky et al.
; Khapko et al. In wholly single-phase flows, or two- or multiphase flows where the phases are homogeneously mixed, fluid motion is invisible to the eye.
The introduction of tracer particles into the flow enables flow patterns and behavior to be rmore, tracking the motion and behavior or these particles, either individually of as groups, allows the fluid motion to measured. both before tracer injection (for background analysis) and again during tracer injection.
The water and steam samples are analyzed for tracer content, and the mass flowrate of each phase is calculated based on these measured concentrations and the injection rate of each tracer.
The mass rate of liquid and steam is given by: Equation 1. Large Eddy Simulation of Transitional Flow in an Idealized Stenotic Blood Vessel: Evaluation of Subgrid Scale Models An Experimental Investigation Using Photochromic Tracer Methods,” Simulation of Scalar Mixing in Co-Axial Jet Flows Using an LES Method.
GT Research of Whirlpool Sound Radiation in Turbulence Coherent Structures. Ethier et al. () described steady-flow separation patterns in a 45° junction that resembles an anastomosis with inlet Reynolds numbers in the range – and zero flow in the DVS. Transition to unsteadiness was observed experimentally at Re= (Re—Reynolds number) by using the photochromic dye tracer technique, but not at Re= Measurement of the degree of dilution of a known quantity of tracer after its mixing in a flowing stream of water is the basis of dilution gaging.
There are two main approaches: (1) the slug-injection of a known amount of tracer into the flow, which requires that the dilution of the tracer be. diffusion coefficient for the airways flow than those evaluated using Equation (1) for smooth pipe. This phe- nomenon is well explained by several researchers .
Compared with obtained data using a solute in water flow, data provided by Keyes  and Taylor  were meas- ured at relatively lower Reynolds number region.
They. A photochromic tracer system for residence time measurements in highly viscous fluids ☆ Author links open overlay panel J.R. Bourne G.K. Giger W. Richarz R. Riesen Show more.Flow Measurement Uncertainty Using Tracer Gas Dilution Method Eric Harman CEESI WCR 37 Nunn, CO