Detailed Experimental Studies of Flow in Large Scale Brush Seal Model and a Comparison With CFD Predictions

2000 ◽  
Vol 122 (4) ◽  
pp. 672-679 ◽  
Author(s):  
L. H. Chen ◽  
P. E. Wood ◽  
T. V. Jones ◽  
J. W. Chew
Keyword(s):  
Large Scale ◽  
Experimental Studies ◽  
Flow Characteristics ◽  
Resistance Coefficient ◽  
Scale Model ◽  
Anisotropic Flow ◽  
Pressure Distributions ◽  
Brush Seal ◽  
Dimensional Parameters ◽  
Measured Pressure

A five times scale model of an engine brush seal has been manufactured. The bristle stiffness and pressure were chosen to satisfy close similarity of the relevant non-dimensional parameters, and the choice of parameters is described. The comparison of flow characteristics for the model seal and an engine seal confirmed the non-dimensional similarity. Detailed pressure measurements were performed within the bristle pack by employing hollow bristles. This novel measurement allowed insight to be obtained into the operation of both clearance and interference seals. In particular, the measured pressure variation in the region of the bristle tips was significant. The deflection of the bristles was determined by comparing the bristle tip pressures with the static pressures along the shaft. Hence the compaction of the pack in this region was found directly. A numerical modeling of brush seals employing anisotropic flow resistance has been developed. Predictions were compared with the measured pressure distributions within the pack. This enabled sensible selection of the pack resistance distribution to be made. Although uniform anisotropic resistance throughout the pack gave reasonable flow rate characteristics, the pressure distribution was not reproduced. A variation of resistance coefficient consistent with the observed compaction was required to give a solution comparable with the experiments. [S0742-4795(00)01703-8]

scholarly journals Detailed Experimental Studies of Flow in Large Scale Brush Seal Model and a Comparison With CFD Predictions

1999 ◽  
Author(s):  
L. H. Chen ◽  
P. E. Wood ◽  
T. V. Jones ◽  
J. W. Chew
Keyword(s):  
Large Scale ◽  
Experimental Studies ◽  
Flow Characteristics ◽  
Resistance Coefficient ◽  
Scale Model ◽  
Anisotropic Flow ◽  
Pressure Distributions ◽  
Brush Seal ◽  
Dimensional Parameters ◽  
Measured Pressure

A five times scale model of an engine brush seal has been manufactured. The bristle stiffness and pressure were chosen to satisfy close similarity of the relevant non-dimensional parameters, and the choice of parameters is described. The comparison of flow characteristics for the model seal and an engine seal confirmed the non-dimensional similarity. Detailed pressure measurements were performed within the bristle pack by employing hollow bristles. This novel measurement allowed insight to be obtained into the operation of both clearance and interference seals. In particular, the measured pressure variation in the region of the bristle tips was significant. The deflection of the bristles was determined by comparing the bristle tip pressures with the static pressures along the shaft. Hence the compaction of the pack in this region was found directly. A numerical modelling of brush seals employing anisotropic flow resistance has been developed. Predictions were compared with the measured pressure distributions within the pack. This enabled sensible selection of the pack resistance distribution to be made. Although uniform anisotropic resistance throughout the pack gave reasonable flow rate characteristics, the pressure distribution was not reproduced. A variation of resistance coefficient consistent with the observed compaction was required to give a solution comparable with the experiments.

Improved Understanding of Blow-Down in Filament Seals

2008 ◽  
Author(s):  
Gervas Franceschini ◽  
Terry V. Jones ◽  
David R. H. Gillespie
Keyword(s):  
Gas Turbines ◽  
Flow Resistance ◽  
Large Scale ◽  
Scale Model ◽  
Blow Down ◽  
Pressure Distributions ◽  
Brush Seal ◽  
Large Scale Model ◽  
Rotor Surface ◽  
Brush Seals

Brush seals are used to provide flow resistance between rotating and stationary components in gas turbines. Compliant filament seals such as brush seals exhibit a phenomenon called blow-down where the filaments deflect towards the rotor surface when a differential pressure is applied across the seal. This phenomenon is desirable as it enables seal contact to be maintained during rotor contractions and eccentric excursions. This paper describes an aerodynamic mechanism which can cause the blow-down of bristles. Importantly it shows that distortion of the bristle pack is not necessary to achieve blow-down. Experimental and computational investigations of a large scale model representative of a section of a brush seal are also reported. The measured and predicted detailed pressure distributions thus obtained are used to validate the model of blow-down presented.

Improved Understanding of Blow-Down in Filament Seals

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Gervas Franceschini ◽  
Terry V. Jones ◽  
David R. H. Gillespie
Keyword(s):  
Gas Turbines ◽  
Flow Resistance ◽  
Large Scale ◽  
Scale Model ◽  
Blow Down ◽  
Pressure Distributions ◽  
Brush Seal ◽  
Large Scale Model ◽  
Rotor Surface ◽  
Brush Seals

Brush seals are used to provide flow resistance between rotating and stationary components in gas turbines. Compliant filament seals, such as brush seals, exhibit a phenomenon called blow-down, where the filaments deflect toward the rotor surface when a differential pressure is applied across the seal. This phenomenon is desirable as it enables seal contact to be maintained during rotor contractions and eccentric excursions. This paper describes an aerodynamic mechanism, which can cause the blow-down of bristles. Importantly it shows that distortion of the bristle pack is not necessary to achieve blow-down. Experimental and computational investigations of a large scale model representative of a section of a brush seal are also reported. The measured and predicted detailed pressure distributions thus obtained are used to validate the model of blow-down presented.

scholarly journals DEVELOPMENT OF PHYSICAL MODEL VEHICLE WITH REMOTIONAL CONTROL FOR EXPERIMENTAL STUDIES OF VEHICLE PROPERTIES

2020 ◽  
Vol 1 (46) ◽  
pp. 341-352
Author(s):  
Timkov O ◽  
◽  
Yashchenko D ◽  
Keyword(s):  
Mathematical Model ◽  
Experimental Study ◽  
Remote Control ◽  
Physical Model ◽  
Large Scale ◽  
Experimental Studies ◽  
Scale Model ◽  
Recording Equipment ◽  
Control Equipment ◽  
The Future

The article is devoted to the development of the physical model of the vehicle, the equipment of the measuring, recording and remote control equipment for the experimental study of the properties vehicles. The construction of the physical model and the used electronic modules is described in detail, references are given to the application libraries and the code of the first part of the program for remote control. In the future, it is planned to develop a mathematical model of the movement of a passenger vehicle and to check its adequacy in conducting experimental studies on maneuverability on a physical model. The aim of the article is developed the physical model of the vehicle, equipped with measuring, recording and remote control equipment, for the experimental study of the properties of vehicle. Materials and research methods: development and designing (experimental research of properties of vehicles on the physical model); remote control; wheeled controlled module. The self-propelled large-scale model of the vehicle, reproducing a passenger car of the category M1, with a controlled wheelbase and a rear drive axle, has been developed. The model is equipped with the necessary measuring and recording equipment and remote control equipment. The software of the model allows you to implement both control manual and the given algorithm. In the future, it is planned to develop a mathematical model of the vehicle motion and to check its adequacy on the developed physical model. The obtained results will allow to improve not only the mathematical model, but also the experimental physical model and proceed further to the study of the properties of hybrid road trains with an active trailer link. KEY WORDS: VEHICLE, PHYSICAL MODEL, EXPERIMENT, STUDY, MODULE, MEMORY CARD, ACCELEROMETER, PROGRAM.

Fluid Dynamic Study in a Femoral Artery Branch Casting of Man With Upstream Main Lumen Curvature for Steady Flow

1985 ◽  
Vol 107 (3) ◽  
pp. 240-248 ◽  
Author(s):  
M. R. Back ◽  
Y. I. Cho ◽  
L. H. Back
Keyword(s):  
Steady Flow ◽  
Fluid Transport ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Pressure Distributions ◽  
Flow Investigation ◽  
Measured Pressure

An in-vitro, steady flow investigation was conducted in a hollow, transparent vascular replica of the profunda femoris branch of man for a range of physiological flow conditions. The replica casting tested was obtained from a human cadaver and indicated some plaque formation along the main lumen and branch. The flow visualization observations and measured pressure distributions indicated the highly three-dimensional flow characteristics with arterial curvature and branching, and the important role of centrifugal effects in fluid transport mechanisms.

Experimental studies in magneto-fluid dynamics: flow over a sphere with a cylindrical afterbody

1969 ◽  
Vol 35 (2) ◽  
pp. 411-416 ◽  
Author(s):  
T. Maxworthy
Keyword(s):  
Magnetic Field ◽  
Fluid Dynamic ◽  
Experimental Studies ◽  
Dynamic Flow ◽  
Composite Body ◽  
Pressure Drag ◽  
Pressure Distributions ◽  
Pressure Profiles ◽  
Measured Pressure ◽  
The Magnetic Field

The measured pressure distributions over the front hemisphere of a hemispherecylinder combination placed in an aligned fields magneto-fluid dynamic flow are presented. Integration of the pressure profiles show that the form or pressure drag of the composite body first increases as the magnetic field strength increases, at a fixed flow velocity, but then decreases as the magnetic field becomes still stronger.

Experimental and Numerical Investigations on the Leakage Flow Characteristics of the Labyrinth Brush Seal

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
Jun Li ◽  
Bo Qiu ◽  
Zhenping Feng
Keyword(s):  
Experimental Data ◽  
Pressure Ratio ◽  
Flow Characteristics ◽  
Leakage Rate ◽  
Navier Stokes ◽  
Leakage Flow ◽  
Blow Down ◽  
Pressure Distributions ◽  
Brush Seal ◽  
Brush Seals

The leakage rate of the labyrinth brush seal was experimentally measured and numerically investigated in this paper. Four different rotational speeds of 0, 1500, 2400 and 3000 rpm were utilized to investigate the effects on the leakage rate of the labyrinth brush seal. In addition, five different pressure ratios and two initial clearances were also adopted to study the influences of pressure ratio and clearance size on the leakage rate of the labyrinth brush seal. The leakage rates of the experimental labyrinth brush seal at different rotational speeds, pressure ratios, and initial clearances were also predicted using Reynolds-averaged Navier-Stokes (RANS) solutions coupling with a non-Darcian porous medium model. The rotor centrifugal growth and bristle blow-down effects were considered in the present numerical research. The rotor centrifugal growth at different rotational speeds was calculated using the finite element method (FEM). The variation of the sealing clearance size with rotor centrifugal growth and bristle blow-down was analyzed. The numerical leakage rate was in good agreement with the experimental data. The effects of rotational speeds, pressure ratios, and clearance sizes on the leakage flow characteristics of brush seals were also investigated based on the experimental data and numerical results. The detailed leakage flow fields and pressure distributions of the brush seals were also presented.

Experimental and Numerical Investigation of a Combustor Model

2011 ◽  
Author(s):  
Darioush G. Barhaghi ◽  
Jacek Janczewski ◽  
Thomas Larsson
Keyword(s):  
Mach Number ◽  
Cross Sections ◽  
Load Condition ◽  
Atmospheric Condition ◽  
Flow Distribution ◽  
Scale Model ◽  
Pressure Distributions ◽  
Pressure Recovery Factor ◽  
Measured Pressure ◽  
Different Parts

Fluid flow behaviour is studied both experimentally and numerically in a combustor model which is recently designed at Siemens Turbomachinery AB at Finspong. The model consists of a full size combustor sector that is surrounded by two half size combustor sectors. The half size sectors provide the pressure drop equal to a full scale combustor sector to guarantee the correct air mass flow distribution through the system. Measurements are performed at atmospheric condition and therefore the boundary conditions are scaled based on the Mach number. This means that the Mach number in different parts of the combustor under the test condition is equal to the Mach number of the flow at full load condition. Pitot tubes and pressure taps are employed to measure the dynamic and static pressures at different cross sections of the model. From the measured pressure, the velocity is calculated. The pressure distributions along the diffusers are compared and the pressure recovery factor is calculated for different cases. The computations are performed using RANS (SST k-ω model) and LES (Smagorinsky sub-grid scale model) methods. The computed and measured results show similar trends although there are rather large discrepancies between the results.

Experimental and Numerical Investigations on the Leakage Flow Characteristics of the Labyrinth Brush Seal

2012 ◽  
Author(s):  
Jun Li ◽  
Bo Qiu ◽  
Shengke Jiang ◽  
Xianglin Kong ◽  
Zhenping Feng
Keyword(s):  
Experimental Data ◽  
Pressure Ratio ◽  
Flow Characteristics ◽  
Leakage Rate ◽  
Navier Stokes ◽  
Leakage Flow ◽  
Blow Down ◽  
Pressure Distributions ◽  
Brush Seal ◽  
Brush Seals

The leakage rate of the labyrinth brush seal was experimentally measured and numerically investigated in this paper. Four different rotational speeds with 0, 1500, 2400 and 3000 rpm were utilized to investigate the effects on the leakage rate of the labyrinth brush seal. In addition, five different pressure ratios and two initial clearances were also adopted to study the influences of pressure ratio and clearance size on the leakage rate of the labyrinth brush seal. The leakage rate of experimental labyrinth brush seal at different rotational speeds, pressure ratios and initial clearances were also predicted using Reynolds-Averaged Navier-Stokes (RANS) solution coupling with non-Darcian porous medium model. The rotor centrifugal growth and bristle blow-down effects were considered in the present numerical research. The rotor centrifugal growth at different rotational speeds was calculated using Finite Element Method (FEM). The variation of sealing clearance size with rotor centrifugal growth and bristle blow-down was analyzed. The numerical leakage rate was in good agreement with the experimental data. The effects of rotational speeds, pressure ratios and clearance sizes on the leakage flow characteristics of brush seals were also investigated based on the experimental data and numerical results. The detailed leakage flow fields and pressure distributions of brush seals were also presented.

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