An Experimental Study of Fluid Flow in Disk Cavities

1992 ◽  
Vol 114 (2) ◽  
pp. 454-461 ◽  
Author(s):  
S. H. Bhavnani ◽  
J. M. Khodadadi ◽  
J. S. Goodling ◽  
J. Waggott
Keyword(s):  
Experimental Study ◽  
Fluid Flow ◽  
Gas Turbine ◽  
Experimental Studies ◽  
Reynolds Numbers ◽  
Turbine Disk ◽  
Published Data ◽  
Disk System ◽  
Flow Rates ◽  
Pressure Distributions

Results are presented for an experimental study of fluid flow in models of gas turbine disk cavities. Experiments were performed on 70-cm-dia disks for rotational Reynolds numbers up to 2.29 × 106. Velocity and pressure distributions are presented and compared to previous theoretical and experimental studies for a free disk, and an unshrouded plane Rotor–Stator disk system. Minimum coolant flow rates for the prevention of ingress, determined for the case of a simple axial rim seal, compare well with previously published data.

An Experimental Study of Fluid Flow in Disk Cavities

1991 ◽  
Author(s):  
S. H. Bhavnani ◽  
J. M. Khodadadi ◽  
J. S. Goodling ◽  
J. Waggott
Keyword(s):  
Experimental Study ◽  
Fluid Flow ◽  
Gas Turbine ◽  
Experimental Studies ◽  
Reynolds Numbers ◽  
Turbine Disk ◽  
Published Data ◽  
Disk System ◽  
Flow Rates ◽  
Pressure Distributions

Results are presented for an experimental study of fluid flow in models of gas turbine disk cavities. Experiments were performed on 70 cm diameter disks for rotational Reynolds numbers up to 2.29 × 106. Velocity and pressure distributions are presented and compared to previous theoretical and experimental studies for a free disk, and an unshrouded and shrouded plane rotor-stator disk system. Minimum coolant flow rates for the prevention of ingress, determined for the case of a simple axial rim seal, compare well with previously published data.

scholarly journals Fluctuations of the non-Newtonian fluid flow in a Kenics static mixer: An experimental study

2008 ◽  
Vol 10 (3) ◽  
pp. 35-37 ◽  
Author(s):  
Sylwia Peryt-Stawiarska ◽  
Zdzisław Jaworski
Keyword(s):  
Experimental Study ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Newtonian Fluid ◽  
Strong Dependence ◽  
Reynolds Numbers ◽  
Velocity Profiles ◽  
Test Fluid ◽  
Static Mixer ◽  
Flow Fluctuations

Fluctuations of the non-Newtonian fluid flow in a Kenics static mixer: An experimental study The measurements for a Kenics static mixer were carried out using Laser Doppler Anemometer (LDA). The test fluid was non-Newtonian solution of CMC, Blanose type 9H4. The velocity data inside the 5th Kenics insert were collected for the axial components at five levels of Reynolds number, Re = 20 ÷ 120. Velocity fluctuations were also analyzed in the frequency domain, after processing them with the help of the Fast Fourier Transform (FFT) procedure. The spectra of fluctuations provided information about level of the fluctuations in the observed range of Reynolds number. The obtained data were then also used to plot the velocity profiles for the fifth insert of the Kenics mixer. It was concluded that in the investigated range of Reynolds numbers (Re = 20 ÷ 120) a strong dependence of the velocity profiles and the flow fluctuations on Reynolds number was observed.

Fluid Flow Structures in Staggered Banks of Cylinders Located in a Channel

1995 ◽  
Vol 117 (1) ◽  
pp. 36-44 ◽  
Author(s):  
M. J. Braun ◽  
V. V. Kudriavtsev
Keyword(s):  
Fluid Flow ◽  
Numerical Experiments ◽  
Reynolds Numbers ◽  
Flow Structures ◽  
Wall Jet ◽  
Square Channel ◽  
Pressure Distributions ◽  
Geometric Configurations ◽  
Model Fluid ◽  
Flow Through

This paper contains numerical experiments that model fluid flow through a staggered array of cylinders and represents a continuation of work previously performed by the authors (Braun et al., 1993; Kudriavstsev et al., 1993). The results shown here concentrate on the analysis of the physics of flow and pressure distribution in (i) one row of cylinders, and (ii) seven rows of cylinders. The test section is the same square channel described by Braun et al. (1993). The numerical experiments were run in transient mode at Reynolds numbers (Re = umaxd/v) ranging from 86 to 869. The primary purpose of this paper is to report qualitative results regarding the attached near-wall jet phenomenon and to discuss its flow mechanics. The authors compare various stages of the transient evolution of the flow structures for geometric configurations that contain one, and seven rows of pins respectively. The associated pressure distributions in the arrays of pins are also discussed.

Numerical Simulation and Experimental Study of Gas Flow Dynamics in Porous Media: Application in Cold Box Foundry Process

2003 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt
Keyword(s):  
Experimental Study ◽  
Numerical Simulations ◽  
Gas Flow ◽  
Electronic System ◽  
Flow Rates ◽  
Contour Maps ◽  
Pressure Distributions ◽  
Computer Controlled ◽  
Cold Box ◽  
Good Agreement

The results of an experimental study and 3D numerical simulations of resin bonded sand/air flow in a square corebox with an H-shape insertion and passage between upper and lower pockets of the pattern are presented. A computer controlled electronic system was designed and built to measure pressures and flow rates inside the corebox during mold filling, gassing and purging cycles of Phenolic Urethane Amine (PUA) process. Contour maps of the pressure distributions inside the corebox were created based on barometric measurements. A good agreement between experimental results and numerical simulations was found.

Mainstream Ingress Suppression in Gas Turbine Disk Cavities

1994 ◽  
Vol 116 (2) ◽  
pp. 339-346 ◽  
Author(s):  
V. I. Khilnani ◽  
L. C. Tsai ◽  
S. H. Bhavnani ◽  
J. M. Khodadadi ◽  
J. S. Goodling ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Laser Sheet ◽  
Reynolds Numbers ◽  
Labyrinth Seal ◽  
Turbine Disk ◽  
Scale Model ◽  
Design Data ◽  
Outer Periphery ◽  
Visualization Experiments ◽  
Good Agreement

The sealing characteristics of an air-cooled gas turbine disk cavity have been studied using laser sheet flow visualization. Experiments were performed on a simplified half-scale model of an actual gas turbine disk cavity. This type of rotor–stator geometry with a double-toothed-rim (DTR) seal at the outer periphery and a labyrinth seal at the inner periphery of the cavity has been tested for its ability in preventing ingress of hot mainstream gases. The results show good agreement with previously esimated design data. Experiments were conducted for various labyrinth seal flow rates and rotational Reynolds numbers up to 1.52 × 106. The effects of rotor eccentricity on minimum purge flows have also been discussed.

Experimental Study of Particle-Liquid Flow Behaviour in a Microchannel Attached to an Inlet Reservoir

2008 ◽  
Author(s):  
Clement K. M. Kong ◽  
Sasan Raghibizadeh ◽  
Masahiro Kawaji
Keyword(s):  
Experimental Study ◽  
Fluid Flow ◽  
Liquid Mixture ◽  
Average Distance ◽  
Liquid Mixtures ◽  
Average Density ◽  
Flow Rates ◽  
Carrier Fluid ◽  
Square Microchannel ◽  
Cylindrical Reservoir

An experimental study of a solid particle-liquid mixture in a microchannel was conducted by injecting a particle-liquid mixture into a 3.0 mm diameter cylindrical reservoir connected to a square microchannel. Glass particles with diameters ranging from 8 to 12 μm and density between 0.95 and 1.15g/ml, as well as polystyrene particles with diameters ranging from 8 to 50μm and an average density of 1.03–1.05 g/ml were mixed with de-ionized water to create particle-liquid mixtures. The mixture could be continuously stirred in the reservoir using a small magnetic stir bar. The number of particles entering the microchannel was found to depend on the concentration and density of the particles in the reservoir, stirring and fluid flow rates. The particles with a density larger than the carrier fluid entered the microchannel, settled at the bottom of the channel and became immobile at low fluid flow rates, blocking the subsequent particle flow. In many cases, the particles flowed in small groups or clusters, which were separated by short distances. The average distance between the particles or particle clusters was found to vary both with the stirring rate in the reservoir as well as the fluid flow rate in the microchannel.

scholarly journals Wind Tunnel Investigation into the Resistance Analysis of Slender Body Catamaran

Kapal ◽  
2020 ◽  
Vol 17 (2) ◽  
pp. 65-73
Author(s):  
I Ketut Aria Pria Utama ◽  
S Sutiyo ◽  
Bagiyo Suwasono
Keyword(s):  
Experimental Study ◽  
Form Factor ◽  
Wind Tunnel ◽  
Flow Velocity ◽  
Pressure Coefficient ◽  
Form Factors ◽  
Reynolds Numbers ◽  
Slender Body ◽  
Published Data ◽  
Velocity Changes

The Wind tunnel investigation of a slender body catamaran was conducted in order to determine its resistance characteristics, namely the effect of pressure and flow velocity changes for varied hull separation. The catamaran was tested in a wind tunnel belongs to Department of Mechanical Engineering, ITS, with hull separations of  S/L = 0.2 to 0.4 and variation in Reynolds numbers up to 4.46 x 105. Pressure around the hull was measured using pressure tappings and the flow velocity behind the hull was also measured using a Pitôt-static tube. The experimental study shows that the pressure coefficient decreases when the hull separation declines and conversely, the flow velocity increases. The tests demonstrated a viscous interaction between the hulls, and form factors for the monohull and catamaran are derived. The demihull exhibited a form factor (1+k) of 1.265 and in the catamaran mode, the measured form factor (1+βk) was between 1.416 and 1.403. The results are in agreement with other published data.

Effect of Pin Fins on Jet Impingement Heat Transfer on A Rotating Disk

2021 ◽  
Author(s):  
Pratik S. Bhansali ◽  
Kishore Ranganath Ramakrishnan ◽  
Srinath Ekkad
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Jet Impingement ◽  
Rotating Disk ◽  
Disk Surface ◽  
Reynolds Numbers ◽  
Turbine Disk ◽  
Large Space ◽  
Air Jet ◽  
Pin Fins

Abstract Heat transfer on rotating surfaces is a predominant phenomenon in rotating machinery as in the case of the gas turbine disk. The gas turbine disk needs to be cooled as well as protected from the ingress of hot turbine gases in the stator-rotor cavity. In the current study, an experimental investigation of the heat transfer of an impinging air jet on a surface rotating at low rotational Reynolds number has been carried out. Addition of pin-fins on the disk surface is an effective way to enhance the heat transfer between the disk and the jet of cooling air. The effect of addition of an inline array of square pin fins on the rotating disk heat transfer has been investigated in this study. Steady state measurements have been carried out using thermocouples embedded at different locations in an aluminum disk with an array of square pin-fins rotating in a large space. Experiments have been conducted at rotational Reynolds numbers (ReR) of 5,487–12,803 based on the disk diameter (D) and jet Reynolds numbers (Re) of 5,000–18,000 based on the jet diameter (d). Two different ratios of jet to nozzle spacing and jet diameter (z/d) of 2 and 4 and three different impingement locations – at eccentricities (ε) – 0, 0.33 and 0.67 have been considered. The diameter of the impinging jet has been kept constant in order to maintain an equal jet footprint across all the cases. The area averaged Nusselt number over the surface with pin fins has been compared with a smooth rotating disk of equal diameter. Results indicate that for the smooth surface, ε and ReR have negligible effect on Nu. However, addition of pin fins enhance Nu by a factor between 1.5 and 3.9 in the present study. Qualitative visualization of flow field has been performed using the commercial simulation package Ansys Fluent to further understand the heat transfer trends.

CFD Simulations and Experimental Study of Two-Phase Flow in Sand Coremaking Process

2002 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt
Keyword(s):  
Experimental Study ◽  
Numerical Simulations ◽  
Electronic System ◽  
Cfd Simulations ◽  
Two Phase ◽  
Flow Rates ◽  
Contour Maps ◽  
Pressure Distributions ◽  
Computer Controlled ◽  
Good Agreement

The results of an experimental study and 3D numerical simulations of resin bonded sand/air flow in a square corebox with an H-shape insertion and passage between upper and lower pockets of the pattern are presented. A computer controlled electronic system was designed and built to measure pressures and flow rates inside the corebox during mold filling, gassing and purging cycles of Phenolic Urethane Amine (PUA) process. Contour maps of the pressure distributions inside the corebox were created based on barometric measurements. A good agreement between experimental results and numerical simulations was found.

Thoracoabdominalis aortakirekesztés során fellépő elektrofiziológiai változások a gerincvelőben

2020 ◽  
Vol 73 (4) ◽  
pp. 160-166
Author(s):  
Csaba Dzsinich ◽  
Péter Gloviczki ◽  
Gabriella Nagy ◽  
Klaudia Vivien Nagy
Keyword(s):  
Spinal Cord ◽  
Motor Evoked Potentials ◽  
Spinal Cord Ischemia ◽  
Experimental Studies ◽  
Neuron Specific Enolase ◽  
Neurological Complications ◽  
Neurologic Outcome ◽  
Published Data ◽  
Aortic Clamping ◽  
Sensory Evoked

Összefoglaló. A thoracoabdominalis aortakirekesztés okozta gerincvelő ischemia súlyos neurológiai következményeit számos klinikai és kísérleti tanulmány bizonyítja. E nehezen kiszámítható, súlyos szövődmény megelőzésének érdekében régi törekvés megfelelő intra- és posztoperatív monitorizálás kifejlesztése, ami előre jelzi a gerincvelő-funkció romlását, illetve a kialakuló celluláris károsodást. A legelterjedtebb, a klinikai gyakorlatban széles körben alkalmazott megoldás a gerincvelői kiváltott motoros potenciál (MEP) folyamatos ellenőrzése. Ritkábban alkalmazott – bár ígéretes – eljárás a biokémiai változások nyomon követése, ami a sejtszintű károsodás markereit használja fel az ischemia okozta változások felismerésére. Korábbi dolgozatunkban kutyákon végzett kísérleteink azon eredményeit ismertettük, amelyekben a 60 perces thoracoabdominalis aortakirekesztés okozta neurológiai változások és a perfúzió adatainak összefüggéseit tárgyaltuk. Jelen tanulmányunkban a gerincvelői motoros (MEP) és szenzoros (SEP) kiváltott potenciálok változásait vizsgáljuk a neurológiai végállapot vonatkozásában. Megállapítottuk, hogy SEP változásai a neurológiai károsodás mértékével értékelhető összefüggést nem mutatnak. A MEP-amplitúdó és -latencia értékei biztonsággal jelzik a fenyegető gerincvelő ischemiát. A neurológiai deficit mélységét (Tarlov 2,1,0) a MEP-értékek változásai numerikusan nem értékelhetően követik. Summary. Severe neurological complications of the thoracoabdominal aortic clamping were published in numerous clinical and experimental studies. These hardly predictable, devastating consequences demanded to develop a monitoring system which might detect impending level of spinal cord ischemia in time – in order to introduce or enhance protective procedures and prevent permanent neurological deficit. The most widely used monitoring in clinical practice is the continuous surveillance of the motor evoked potentials (MEP) during and after thoracoabdominal aortic clamping. Much less used, but promising opportunity is to control the metabolic changes and cellular integrity utilizing specific markers like liquor lactate and neuron specific enolase (NSE) etc. In our earlier study we published data of our canine experiment related to coherencies between neurological outcome and specific perfusion of the spinal cord during and after one hour thoracoabdominal aortic clamping. In the present paper we investigate the behavior of motor evoked (MEP) and sensory evoked (SEP) potentials related to neurological changes. We conclude the behavior of SEP values hardly correlate with the neurologic outcome, meanwhile decrease of MEP amplitude provides reliable signal for developing spinal cord ischemia. We could not confirm a numeric correlation of these data and the level of the final neurologic outcome.

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