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2 edition of Flow regimes in conical diffusers. found in the catalog.

Flow regimes in conical diffusers.

Bernard Lister

Flow regimes in conical diffusers.

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  • 40 Currently reading

Published by University of Salford in Salford .
Written in English


Edition Notes

MSc thesis, Aeronautical and Mechanical Engineering.

ID Numbers
Open LibraryOL19685073M

conditions, where the flow is not symmetrical and, moreover, transient. So, in a conical diffuser with large internal angle the flow separates and attaches to part of the wall in random way. The position of separation zone varies randomly along circumference of .   The diffuser system Centrifugal compressors and pumps are, in general, fitted with either a vaneless or a vaned diffuser to transform the kinetic energy at the impeller outlet into static pressure. The volute or scroll is the final component of a centrifugal compressor or pump (Figure ). This is a spiral-shaped channel of increasing cross-sectional.


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Flow regimes in conical diffusers. by Bernard Lister Download PDF EPUB FB2

Loss coefficient of conical diffusers are presented. The Reynolds: number of water flow may he up to 3*5x10'% Area ratios of the down¬ stream pipes to the upstream pipe were,l6:l, and The cone angles of the diffusers were 10°, 3°% 45°, 60°, 90°, ° and l80°.

Fully developed turbulent flow entered the diffusers. Chart Depicting Flow Regimes for two-Dimensional Diffusers Adapted from Sovran and Klomp, Figure shows typical performance curves for a rectangular diffuser * with a fixed sidewall to length ratio, L / W 1 =given by Kline, Abbott, and Fox ().

Results of experimental investigations of the turbulent swirl flow in three straight conical diffusers with various diffuser total angles are presented in this paper. All three diffusers have the inlet diameter m and total divergence angles °, ° and °. The incompressible swirl flow field is File Size: KB.

to predict conical mance in the high-speed flow regime. In the past, the flow in a diffuser has been analyzed by assuming that the diffuser flow can be approximated by a thin boundary layer adjacent to the wall and an inviscid ' core in the center of the passage.

This type of File Size: 1MB. ELSEVIER Turbulent Flow in a Conical Diffuser: A Review Ram S. Azad Department of Mechanical and Industrial Engineering, University of Manitoba, Winnipeg, Manitoba, Canada This is a review of experimental studies of turbulent flow in a conical diffuser by eight Ph.D.

students, eleven students, one stu- dent, and myself in the past 29 by: THESIS PERFORMANCE AND FLOW REGIMES IN PLANE 2-D DIFFUSERS WITH EXIT CHANNELS AT LOW REYNOLDS NUMBERS by Epameinondas Trivilos September Thesis Advisor: Knox T.

Millsaps Approved for public release; distribution is unlimited. Most studies Flow regimes in conical diffusers. book flow characteristics in diffusers were experimental.

As reviewed by Klein [19] and summarized by Azad [21], experimental results show that the inlet conditions, turbulence and swirl, collectively affect conical diffuser performance and that swirl is the most effective way to prevent flow separation [19], [ The Radial Flow Diffuser (RFD)’s patented construction is designed to handle large volumes of air with extremely short throws to minimize velocity in the occupied zone.

Ideal for use in laboratories, the RFD is able to provide large volumes of make-up air, at low velocity. Investigation of the Turbulent Swirl Flows in a Conical S THERMAL SCIENCE: YearVol. 14, Suppl., pp. SS the diffusers after axial pump impellers, as well as in conical diffuser behind the axial fan runners and in many other diffuser passages with internal swirl flow.

Direct numerical simulations of turbulent flow in a conical diffuser insufficient for modeling the complex flow regimes near diffuser corners, as observed in DNS of conical diffusers.

The flow path approximates the so-called fishtail diffuser utilized on small gas turbine engines for the transition between the centrifugal impeller and the combustion chamber. Two variations of the inlet flow, differing in boundary layer thickness and turbulence intensity, are by: 7.

An Internet Book on Fluid Dynamics Diffusers and nozzles In the specific case of steady flow in a diffuser the loss coefficient is defined as, Figure 1: Diffuser performance (1−η where η is the diffuser efficiency).

K = 2gΔH u2 1 (Bfe1) and the value of η =1− K 1− A21 A2 2 (Bfe2) is often referredto as the diffuser Size: KB. Straight Conical Diffuser Multistage Conical Diffusers Stepped Conical Diffuser Two-Stage Conical Diffuser Curved Wall Diffuser Pipe Reducer: Expanding References Further Reading 12 EXITS Discharge from a Straight Pipe Discharge from a Conical Diffuser book.

After Miller, Agrawal and Singh () were the first to focus on the flow in a large area ratio curved diffuser. They carried out flow visualization studies in a 90° large area ratio curved diffuser with an elliptical centerline.

Detailed flow characteristics of the same Cited by: 1. In order to study swirling, confined, turbulent and non cavitating flow in conical diffusers, a series of 2D LDV and pitot measurements are described.

A tangential entry swirl flow inducer was used to generate the swirl flow, LDV was used for the measurements of velocity distribution, and a three hole pitot tube was used for the pressure Author: Ole Gunnar Dahlhaug.

Pipe Flow provides the information required to design and analyze the piping systems needed to support a broad range of industrial operations, distribution systems, and power plants. Throughout the book, the authors demonstrate how to accurately predict and manage pressure loss while working with a variety of piping systems and piping : $   Influence of curvature distribution and area-ratio (AR) distribution on the pressure fields within the curved annular diffuser are discussed.

General guidelines for end-wall contouring to control the pressure gradients on the diffuser walls are evolved and further demonstrated through computational fluid dynamics (CFD) simulations. The static pressure recovery is observed to be comparable to the published performance of conical diffusers with equivalent included angle and area ratios.

Furthermore, both the static pressure recovery and the total pressure losses are observed to be relatively insensitive to Cited by: The flow fields of four diffusers situated at the rear of a one-stage axial flow compressor were experimentally investigated.

Through modification of the compressor operating point, a wide range of variations of the side wall boundary layers and the radial velocity distribution outside of the boundary layers at diffuser inlet could be achieved.

In many practical applications of conical diffusers, the flow is fed by an annular flow passage formed by a center body. Flow separation, which occurs if the center body ends abruptly, is undesirable because it degrades the diffuser performance.

The present experiment utilizes magnetic resonance velocimetry to acquire three-component mean velocity measurements for a set of conical Cited by: Abstract The turbulent flow in a conical diffuser is predicted adapting the boundary layer calculation method of Bradshaw, Ferris and Atwell.

The predicted mean velocity and shear stress profiles, using the experimental data as initial input, agree well with the measured profiles. Flow Diffusers.

Flow diffusers are for hydraulic high-speed return lines, to slow down fluids entering the reservoir. They help cure foaming problems and prevent cavitation caused by flow disturbance at the pump inlet. They allow greater freedom in reservoir design, and may even eliminate the need for. The Laminar Flow Diffuser with HEPA Filter has been designed to suit the stringent requirements of modern operating rooms and other clean spaces.

The LFDC provides a means of controlling particle concentration within a room by providing unidirectional laminar airflow with low initial face velocity, supplying clean air to the space without. Experimental and Numerical Study of the Swirling Flow in Conical Journal of Engineering Science and Technology OctoberVol.

9(5) Fig. Test Section of a Diffuser of Semi-angle of 5°, Equivalent to Total Angle of 10º (Dimensions in mm). The diffusers used were 5° File Size: KB. The conical diffuser has a total divergence angle of 8 degrees, an area ratio ofand an inlet diameter of m.

The flow at the inlet of the diffuser is fully developed pipe flow. The instrument most commonly used to read air flow out of diffusers is a Velometer.

Most K-factors in this balancing manual are for a Velometer. The “deflecting vane anemometer”, as it is technically described, gives instantaneous velocity reading. Four readings are File Size: 1MB. International Standard Book Number (Ebook-PDF) This book contains information obtained from authentic and highly regarded sources.

Reasonable efforts. The pressure recovery performance of conical diffusers has been measured for a wide range of geometries and inlet flow conditions.

The approximate level and location (in terms of diffuser geometry. Compressible flow (or gas dynamics) is the branch of fluid mechanics that deals with flows having significant changes in fluid all flows are compressible, flows are usually treated as being incompressible when the Mach number (the ratio of the speed of the flow to the speed of sound) is less than (since the density change due to velocity is about 5% in that case).

This technology aids the turbine to exceed the Betz limit, which states that the maximum kinetic energy extracted from the flow is %. Thus, the present study proposes a mathematical model describing the behavior of the internal velocity for three conical diffusers, taking into account the characteristics of flow around them.

Pipe Flow provides the information required to design and analyze the piping systems needed to support a broad range of industrial operations, distribution systems, and power plants. Throughout the book, the authors demonstrate how to accurately predict and manage pressure loss while working with a variety of piping systems and piping components.

The book draws together and reviews the growing. Annular flow diffusers for gas turbines Flow Regimes in Curved Subsonic Diffusers, Transactions ASME, Journal of Basic Engineering, vol. 84, Series D, pp.Sept.

or to NASA Report CR of July entitled Pressure Recovery Performance of Conical Diffusers at High Subsonic Mach Numbers by F. Dolan and P. Runstadler.). Prediction of Turbulence Quantities for Swirling Flow in Conical Diffusers. AIAA J., Vol, No.3, pp, March [9] F.A. Payette, Henau, and M.

Sabourin. Sensitivity of Draft Tube Flow Predictions to Boundary Conditions. 24th IAHR Symposium on Hydraulic Machinery and Systems, October, Foz Do Iguassu, Brazil. Get this from a library.

Pipe Flow: a Practical and Comprehensive Guide. [Donald C Rennels; Hobart M Hudson] -- Pipe Flow provides the information required to design and analyze the piping systems needed to support a broad range of industrial operations, distribution.

Pipe Flow provides the information required to design and analyze the piping systems needed to support a broad range of industrial operations, distribution systems, and power plants.

Throughout the book, the authors demonstrate how to accurately predict and manage pressure loss while working with a variety of piping systems and piping components.

Flow characteristics of low Reynolds number laminar flow through gradually expanding conical and planar diffusers were investigated. Such diffusers are used in valveless micropumps to effect flow rectification and thus lead to pumping action in one preferential direction.

Four. Some characteristics of the diffusers with different opening angles are also presented (Chandavari V., Palekar M.S., ). Conical diffusers were considered by Lenarcic M.

et al. The authors do not only give the calculations results for different flow regimes, but also offer some optimization methods for diffuser and exit chamber design. flow is %. Thus, the present study proposes a mathematical model describing the behavior of the internal velocity for three conical diffusers, taking into account the characteristics of flow around them.

The proposed model is based on the Biot-Savart's Law. Figure 4: Computational area of the conical dif-fuser. Due to high computational costs during the time-consuming optimization process, the medium h= 2) with about 2 nodes was chosen for all calculations.

Figure 4 illustrates a typical computational grid used in. LOW REYNOLDS NUMBER WATER FLOW CHARACTERISTICS THROUGH RECTANGULAR MICRO DIFFUSERS/NOZZLES WITH A PRIMARY FOCUS ON MAJOR/MINOR PRESSURE LOSS, STATIC PRESSURE RECOVERY AND FLOW SEPARATION by KYLE J.

HALLENBECK B.S. University of Central Florida, A thesis submitted in partial fulfillment of the requirements for the degree of Author: Kyle Hallenbeck.

A typical, subsonic diffuser is a duct that increases in size in the direction of flow. As the duct increases in size, fluid velocity decreases, and static pressure rises. Both mass flow rate and Bernoulli's principle are responsible for these changes in pressure, and velocity.

1 Supersonic Diffusers. Supersonic Diffusers.The influence of inlet velocity distribution on the flow through a plane curved diffuser were significantly different diffuser flow regimes, the variables associated with defining these regimes remained for the calculation of the flow in rotationally symmetric diffusers with the aid of .Fraser Conical Diffuser: Study #1.

Figure 1. The shading of the Mach number for the Fraser subsonic conical diffuser. Introduction. This test case computes incompressible turbulent flow in a conical diffuser, and is referred to as the Fraser (flow A) case from the AFOSR-IFP Stanford Conference on Computation of Turbulent Boundary Layers.