Numerical Prediction to Effects of Manifolds Configuration on Flow in Swirling Flow Exhaust Pipe System

2001 ◽  
Author(s):  
L. Cao ◽  
Huimeng Liu ◽  
Yongchang Liu ◽  
Q. Huang
Keyword(s):  
High Speed ◽  
Swirling Flow ◽  
Tangential Velocity ◽  
Exhaust System ◽  
Swirl Flow ◽  
Energy Utilization ◽  
Particle Dynamic ◽  
Exhaust Pipe ◽  
Typical Structure ◽  
Pipe System

Abstract Compared to conventional Modular Pulse Converter (MPC) system with the typical structure of symmetrical T-junction, a novel swirling flow exhaust pipe system has its advantages especially in reducing collision loss of high-speed gases near junction and having interference-free scavenging and higher energy utilization. The initial junction configuration in swirling flow exhaust system was determined with reference to T-junction in MPC. In order to analyze and compare its flow behaviors, 3D-flow fields of manifold-type junctions in swirling flow exhaust pipe system were performed with the revised KIVA II code. A non-linear algebraic Relynolds stress (ASM) model was considered in this study and comparisons were made with the standard κ–ε turbulence model. For many cases of parametric studies considered, it is found that junction’s configurations have significant influence on the velocity distribution and swirl intensity. 30° swirling flow junction is found to be unreasonable, 45° junction with oblate rectangular type contraction area is recommended in swirl flow pipe exhaust pipe system. 3D-Particle Dynamic Analyzer (PDA) measurement was introduced to measure the axial and tangential velocity components of swirling flow in main pipe. Comparisons of computed and measured velocities reveal that model predictions are in generally reasonable agreement with the measurements, indicating validity of computational code and reliability of prediction model.

Experimental Study on Flow Patterns and Pressure Drop of Decaying Swirling Gas-Liquid Flow in a Vertical Pipe

2020 ◽  
Author(s):  
Jiarong Zhang ◽  
Li Liu ◽  
Shuai Liu ◽  
Hanyang Gu
Keyword(s):  
Pressure Drop ◽  
Flow Regime ◽  
Liquid Flow ◽  
High Speed ◽  
Phase Distribution ◽  
Swirling Flow ◽  
Tangential Velocity ◽  
High Speed Camera ◽  
Vertical Pipe ◽  
Gas Liquid Flow

Abstract Vertical swirling gas-liquid flow is a kind of complex two-phase flow containing a nonzero tangential velocity component in engineering applications. The accurate flow regime characterization, phase distribution information and pressure drop data about vertical swirling flow are the basis for the optimization of steam generator (SG), which can greatly reduce the cost and improve the safety of nuclear plants. To get these key parameters of swirling vertical flow, we have made a comprehensive visualization experiment in a vertical pipe with 30mm diameter and 5m length by high-speed camera. The experimental pipe is separated into swirling part and non-swirling part. We have set three observation section with different vertical heights in the swirling part. Changing the flow rate of water and gas, different swirling flow pattern photos can be captured by high-speed camera. Based on the photos of different positions and image-processing MATLAB code, we can get three flow regime maps and figure out the decaying law of swirling gas-liquid flow. The pressure drop can be recorded by rotameter at each position. The decaying law of pressrure drop can be concluded from it. These data can be a guide for designing gas-liquid separator in SG to improve the efficiency of nuclear plant.

The Measured Analysis of Residential Kitchen Pressure Changed Exhaust Pipe System Characteristics

2011 ◽  
Vol 354-355 ◽  
pp. 711-716 ◽  
Author(s):  
Yue Ren Wang ◽  
Jiu Xu Zhao
Keyword(s):  
Internal Pressure ◽  
Pressure Distribution ◽  
Mutual Influence ◽  
Exhaust System ◽  
Pressure Change ◽  
Pipeline System ◽  
Exhaust Pipe ◽  
Pipe System ◽  
Influence Degree ◽  
System Characteristics

in order to study and analysis on pressure distribution of pipeline system under the conditions of different power, to obtain the mutual influence degree between users. Through multi-storey residential pressure change exhaust system measured under the condition of three pressure changed board, the experimental results are compared and analyzed. The result of this paper obtains pressure of the mains and branch and branch speeds in different conditions. In six floors of 400 * 250 pressure changed type exhaust pipe system, no matter exhaust fan’s volume is high-end or low-end in any conditions can satisfy the exhaust requirements. Pipe internal pressure showed low - high – low.

Decaying Annular Swirl Flow With Inlet Solid Body Rotation

1976 ◽  
Vol 98 (1) ◽  
pp. 33-40 ◽  
Author(s):  
C. J. Scott ◽  
K. W. Bartelt
Keyword(s):  
Experimental Data ◽  
Angular Momentum ◽  
Swirling Flow ◽  
Tangential Velocity ◽  
Swirl Flow ◽  
Working Fluid ◽  
Pressure Probe ◽  
Axial Component ◽  
Profile Shape ◽  
Straight Flow

An experimental investigation of a low-speed turbulent swirling flow in a stationary, concentric, annular duct was made. The experiment involved isothermal air as the working fluid in an annulus with a diameter ratio di/d0 = 0.4, an average axial Reynolds number of 72,000, and an average axial velocity of 15 m/s. The swirl profile initially induced at the inlet was of the forced-vortex type. The rate of swirl, or the magnitude of the tangential velocity relative to the axial component, decayed axially from the inlet. Three different swirl rates were considered, one being straight flow. Extensive measurements were made of the velocity field with a cylindrical pressure probe at seven stations located 1.7 to 32.7 equivalent diameters from the entrance. The specific goals were experimental data on the axial decay of angular momentum and inferred values of the effective turbulent tangential viscosity. Results show a uniform axial decay of angular momentum and a profile shape independent of axial location. An empirical model using tangential eddy diffusivities that vary over the cross-section gave the best description of experimental data. The tangential profile shape and tangential viscosity distribution and magnitude did not depend on the initial rate of swirl.

Numerical simulation of swirling flow effect on the first stage vane film cooling distribution

2016 ◽  
Vol 07 (03) ◽  
pp. 1650031
Author(s):  
Hong Yin
Keyword(s):  
Flow Field ◽  
Film Cooling ◽  
Swirling Flow ◽  
Cooling System ◽  
Leading Edge ◽  
Suction Side ◽  
Local Area ◽  
Swirl Flow ◽  
Flow Effect ◽  
Recirculation Flow

In advanced gas turbine technology, lean premixed combustion is an effective strategy to reduce peak temperature and thus, NO[Formula: see text] emissions. The swirler is adopted to establish recirculation flow zone, enhancing mixing and stabilizing the flame. Therefore, the swirling flow is dominant in the combustor flow field and has impact on the vane. This paper mainly investigates the swirling flow effect on the turbine first stage vane cooling system by conducting a group of numerical simulations. Firstly, the numerical methods of turbulence modeling using RANS and LES are compared. The computational model of one single swirl flow field is considered. Both the RANS and LES results give reasonable recirculation zone shape. When comparing the velocity distribution, the RANS results generally match the experimental data but fail to at some local area. The LES modeling gives better results and more detailed unsteady flow field. In the second step, the RANS modeling is incorporated to investigate the vane film cooling performance under the swirling inflow boundary condition. According to the numerical results, the leading edge film cooling is largely altered by the swirling flow, especially for the swirl core-leading edge aligned case. Compared to the pressure side, the suction side film cooling is more sensitive to the swirling flow. Locally, the film cooling jet is lifted and turned by the strong swirling flow.

Experimental Study of Urea Depositions in Urea-SCR System

2014 ◽  
Vol 937 ◽  
pp. 74-79 ◽  
Author(s):  
Shu Zhan Bai ◽  
Shuai Guo Lang ◽  
Ke Ping Yuan ◽  
Yang Liu ◽  
Guo Xiang Li
Keyword(s):  
Control Strategy ◽  
Structural Design ◽  
Cyanuric Acid ◽  
Exhaust System ◽  
Structure Design ◽  
Exhaust Pipe ◽  
Front End ◽  
Urea Crystallization ◽  
Exhaust Stream ◽  
Scr System

Avoiding the urea deposition in the exhaust stream is one of the basic requirements for SCR system normal application. Unreasonable structure design, machining and installation position all could lead to urea crystallization on the wall of exhaust pipe and the front end surface of the catalyst, in addition, unreasonable control strategy also could deteriorate this phenomenon. The components of the urea depositions are the urea and cyanuric acid analyzed by thermogravimetry - FTIR technology. The integrated injector mounting is designed to alleviate the urea crystallization based on analysis results. The engine test and the vehicle road test are all shown that the optimal structural design and calibration strategies could avoid crystallization and sedimentation effectively in the exhaust system.

Experimental Characterization of Two-Phase Swirl Flow Interacting With a Circular Bluff Body

2021 ◽  
Author(s):  
Rafael Gonzalez Hernandez ◽  
Afshin Goharzadeh ◽  
Mahmoud Meribout ◽  
Lyes Khezzar
Keyword(s):  
High Speed ◽  
Bluff Body ◽  
Transition Period ◽  
Swirl Flow ◽  
Critical Distance ◽  
High Speed Photography ◽  
Flow Loop ◽  
Two Phase ◽  
Air Pocket ◽  
Air Core

Abstract This study presents an experimental investigation of two-phase swirl flow interacting with a circular bluff body. A horizontal and transparent multiphase flow loop is employed to investigate the dynamic of swirl flow close to the circular bluff body. Using high-speed photography, air-core development during the transition period is characterized. Analysis of both instantaneous and averaged images provides key information on air-core length and diameter for steady state conditions. The distance from air-core tip to the disk depends on a critical gas-liquid ratio (GLRc). The presence of air pocket behind the circular bluff body depends on a critical distance to the disk.

Feature Extraction From Time Resolved Reacting Flow Data Sets

2018 ◽  
Author(s):  
H. Ek ◽  
I. Chterev ◽  
N. Rock ◽  
B. Emerson ◽  
J. Seitzman ◽  
...  
Keyword(s):  
Swirling Flow ◽  
Azimuthal Velocity ◽  
Flow Fields ◽  
Swirl Flow ◽  
Reacting Flow ◽  
Data Sets ◽  
Time Resolved ◽  
Recirculating Flow ◽  
Flow Features ◽  
Dynamical Flow

This paper presents measurements of the simultaneous fuel distribution, flame position and flow velocity in a high pressure, liquid fueled combustor. Its objective is to develop methods to process, display and compare large quantities of instantaneous data with computations. However, time-averaged flow fields rarely represent the instantaneous, dynamical flow fields in combustion systems. It is therefore important to develop methods that can algorithmically extract dynamical flow features and be directly compared between measurements and computations. While a number of data-driven approaches have been previously presented in the literature, the purpose of this paper is to propose several approaches that are based on understanding of key physical features of the flow — for this reacting swirl flow, these include the annular jet, the swirling flow which may be precessing, the recirculating flow between the annular jets, and the helical flow structures in the shear layers. This paper demonstrates nonlinear averaging of axial and azimuthal velocity profiles, which provide insights into the structure of the recirculation zone and degree of flow precession. It also presents probability fields for the location of vortex cores that enables a convenient method for comparison of their trajectory and phasing with computations. Taken together, these methods illustrate the structure and relative locations of the annular fluid jet, recirculating flow zone, spray location, flame location, and trajectory of the helical vortices.

Liquid Sheet Disintegration and Atomization Process on a Simplified Airblast Atomizer

1993 ◽  
Vol 115 (3) ◽  
pp. 461-466 ◽  
Author(s):  
G. Lavergne ◽  
P. Trichet ◽  
P. Hebrard ◽  
Y. Biscos
Keyword(s):  
High Speed ◽  
Swirling Flow ◽  
Video Camera ◽  
Frequency Instability ◽  
Liquid Sheet ◽  
Processing Unit ◽  
Spray Formation ◽  
High Speed Video Camera ◽  
The Mean ◽  
Component Phase

Liquid sheet break-up in coflowing shear flow is the mean by which liquids are atomized in practical injectors for gas turbine combustors. The present study explores experimentally the mechanisms of liquid sheet instabilities and spray formation. Experiments are conducted on four airblast geometries. A high-speed video camera associated with an image processing unit was used to study the liquid sheet instabilities. A microphone and a frequency analyzer were used to track the disintegration frequency. Instability amplitude and disintegration length of the liquid sheet were measured. A two-component Phase Doppler Particle Analyzer was used to characterize the resultant spray. The spatial distribution of the particle size is influenced by the swirling flow field. These experimental results will be used to assess models of fuel sheet instabilities and disintegration.

The Model Analysis of Inclusion Moving in the Swirl Flow Zone Sourcing from the Inner-Swirl-Type Turbulence Controller in Tundish

2017 ◽  
Vol 36 (5) ◽  
pp. 541-550 ◽  
Author(s):  
Yan Jin ◽  
Chen Ye ◽  
Xiao Luo ◽  
Hui Yuan ◽  
Changgui Cheng
Keyword(s):  
Flow Field ◽  
Swirling Flow ◽  
Mathematic Model ◽  
Swirl Flow ◽  
Water Model ◽  
Medium Size ◽  
Force Analysis ◽  
Inclusion Removal ◽  
Flow Band ◽  
Turbulence Inhibitor

AbstractIn order to improve the inclusion removal property of the tundish, the mathematic model for simulation of the flow field sourced from inner-swirl-type turbulence controller (ISTTC) was developed, in which there were six blades arranged with an eccentric angle (θ) counterclockwise. Based on the mathematical and water model, the effect of inclusion removal in the swirling flow field formed by ISTTC was analyzed. It was found that ISTTC had got the better effect of inhibiting turbulence in tundish than traditional turbulence inhibitor (TI). As the blades eccentric angle (θ) of ISTTC increasing, the intensity of swirling flow above it increased. The maximum rotate speed of fluid in swirling flow band driven by ISTTC (θ=45°) was equal to 25 rmp. Based on the force analysis of inclusion in swirling flow sourced from ISTTC, the removal effect of medium size inclusion by ISTTC was attributed to the centripetal force (Fct) of swirling flow, but removal effect of ISTTC to small size inclusion was more depend on its better turbulence depression behavior.

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