Improvement to Numerical Predictions of Aerodynamic Flows Using Experimental Data Assimilation

1999 ◽  
Vol 36 (4) ◽  
pp. 736-736
Author(s):  
G. Barakos ◽  
D. Drikakis ◽  
W. Lefebre
Keyword(s):  
Experimental Data ◽  
Data Assimilation ◽  
Numerical Predictions ◽  
Aerodynamic Flows

Improvement to Numerical Predictions of Aerodynamic Flows Using Experimental Data Assimilation

1999 ◽  
Vol 36 (3) ◽  
pp. 611-614 ◽  
Author(s):  
G. Barakos ◽  
D. Drikakis ◽  
W. Lefebre
Keyword(s):  
Experimental Data ◽  
Data Assimilation ◽  
Numerical Predictions ◽  
Aerodynamic Flows

Full 3D Conjugate Heat Transfer Simulation and Heat Transfer Coefficient Prediction for the Effusion-Cooled Wall of a Gas Turbine Combustor

2008 ◽  
Author(s):  
Andreas Jeromin ◽  
Christian Eichler ◽  
Berthold Noll ◽  
Manfred Aigner
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Gas Turbine ◽  
Conjugate Heat Transfer ◽  
Solid Wall ◽  
Heat Fluxes ◽  
Computational Domain ◽  
Transfer Coefficients ◽  
Wall Functions ◽  
Numerical Predictions

Numerical predictions of conjugate heat transfer on an effusion cooled flat plate were performed and compared to detailed experimental data. The commercial package CFX® is used as flow solver. The effusion holes in the referenced experiment had an inclination angle of 17 degrees and were distributed in a staggered array of 7 rows. The geometry and boundary conditions in the experiments were derived from modern gas turbine combustors. The computational domain contains a plenum chamber for coolant supply, a solid wall and the main flow duct. Conjugate heat transfer conditions are applied in order to couple the heat fluxes between the fluid region and the solid wall. The fluid domain contains 2.4 million nodes, the solid domain 300,000 nodes. Turbulence modeling is provided by the SST turbulence model which allows the resolution of the laminar sublayer without wall functions. The numerical predictions of velocity and temperature distributions at certain locations show significant differences to the experimental data in velocity and temperature profiles. It is assumed that this behavior is due to inappropriate modeling of turbulence especially in the effusion hole. Nonetheless, the numerically predicted heat transfer coefficients are in good agreement with the experimental data at low blowing ratios.

Energy potential and economic analysis of hydrokinetic turbines implementation in rivers: An approach using numerical predictions (CFD) and experimental data

2019 ◽  
Vol 143 ◽  
pp. 648-662 ◽  
Author(s):  
Ivan Felipe Silva dos Santos ◽  
Ramiro Gustavo Ramirez Camacho ◽  
Geraldo Lúcio Tiago Filho ◽  
Antonio Carlos Barkett Botan ◽  
Barbara Amoeiro Vinent
Keyword(s):  
Experimental Data ◽  
Economic Analysis ◽  
Energy Potential ◽  
Hydrokinetic Turbines ◽  
Numerical Predictions

Experimental and Numerical Studies of Heat Transfer in Human Uteri During Cryoablation

2002 ◽  
Author(s):  
Jim S. Chen ◽  
Kevin Agnissey ◽  
Marla Wolfson ◽  
Charles Philips ◽  
Thomas Shaffer
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Temperature History ◽  
Rubber Sheet ◽  
Numerical Studies ◽  
Numerical Predictions ◽  
Silicone Rubber Sheet ◽  
Nicolson Scheme ◽  
Sheet Good ◽  
Good Agreement

This paper presents experimental and numerical studies of transient heat transfer inside the uterus during application of a PFC (perfluorochemical) fluid into the endometrium cavity in order to achieve cryoablation. The numerical prediction is based on a 1-D finite difference method of the bio-heat equation using the Crank Nicolson scheme. The numerical method is first validated by a 1-D physical model by measuring temperature history at several locations within a silicone rubber sheet. Good agreement, thus positive predictability, was obtained by comparing numerical predictions with the experimental data obtained from eight intact, hysterectomized uteri during cryoablation.

Numerical analysis of seismically induced liquefaction in earth embankment foundations. Part I. Benchmark model

2003 ◽  
Vol 40 (4) ◽  
pp. 753-765 ◽  
Author(s):  
Ogun Aydingun ◽  
Korhan Adalier
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Analysis Procedure ◽  
Finite Element Code ◽  
Remedial Measures ◽  
Foundation Soil ◽  
Benchmark Model ◽  
Numerical Predictions ◽  
Earth Embankment ◽  
Fully Coupled

A numerical analysis has been performed for a clayey embankment founded on a liquefiable foundation soil using an effective stress based, fully coupled, finite element code called DIANA-SWANDYNE II. The results were compared with data obtained from centrifuge experiments. In Part I, the numerical method and the analysis procedure are explained. The results obtained for a series of three consecutive, increasing amplitude shaking events are presented. An attempt has been made to calibrate a benchmark model to be used in the application of different remedial measures which are discussed in Part II. The numerical predictions compared well with the experimental data and provided further insights into the dynamic behavior of embankment–foundation systems.Key words: liquefaction, numerical modeling, coupled formulation, centrifuge, embankment, earthquakes.

Prediction of the Trajectory of Triple Jets in a Uniform Crossflow

1983 ◽  
Vol 105 (1) ◽  
pp. 91-97 ◽  
Author(s):  
T. Makihata ◽  
Y. Miyai
Keyword(s):  
Experimental Data ◽  
Integral Equation ◽  
Flow Pattern ◽  
Velocity Ratio ◽  
Jet Flow ◽  
Numerical Prediction ◽  
Numerical Predictions ◽  
Prediction Technique ◽  
Conservation Of Momentum ◽  
Momentum Integral

This paper describes the results of numerical prediction of the trajectories of turbulent triple jets issuing into a uniform crossflow. The prediction technique is based on the momentum integral equation and the law of conservation of momentum, together with the interference of the triple jets under the assumption of an axially symmetrical flow pattern for each of the jets. Results are presented for both triple buoyant and nonbuoyant jets, with the velocity ratio of jet flow to crossflow ranging from 3.0 to 10.6. The numerical predictions agree well with authors’ and other experimental data.

Large Eddy Simulations of Taylor-Go¨rtler Instabilities in Transitional and Turbulent Boundary Layers

2010 ◽  
Author(s):  
Sergej Gordeev ◽  
Robert Stieglitz ◽  
Volker Heinzel
Keyword(s):  
Experimental Data ◽  
Free Surface ◽  
Liquid Metal ◽  
Boundary Layers ◽  
High Power ◽  
Turbulent Boundary Layers ◽  
Numerical Predictions ◽  
Back Plate ◽  
Exit Nozzle ◽  
Large Eddy

Free surface liquid metal targets are considered in several high power targets as a tool to produce secondary particles, since their power density exceeds material sustainable limits. Many target designs consider due to the high power deposited in the liquid a concave formed back plate in order to yield a higher boiling point. Upstream the free surface target domain the liquid metal flow is conditioned by a nozzle. However, a back-wall curvature as well as a concave shaped exit nozzle contour can lead to the occurrence of secondary motions in the flow caused by Taylor-Go¨rtler (TG) instabilities. These motions may impact the hydrodynamic stability the flow and also lead to an undesired heat transfer from the hottest region produced within the liquid target towards the uncooled back plate. In this study, the suitability of the Large Eddy Simulation (LES) technique to simulate the formation, development and destruction TG instabilities in transitional and turbulent boundary layers was tested by comparing the simulation results with experimental data reported in literature. All comparisons exhibit a qualitative and quantitative good agreement between experimental data and numerical predictions regarding the mean flow parameters and unsteady large-scale structures caused by TG instabilities.

Leading-Edge Film-Cooling Physics: Part II — Heat Transfer Coefficient

2002 ◽  
Author(s):  
William D. York ◽  
James H. Leylek
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Film Cooling ◽  
Leading Edge ◽  
Numerical Predictions ◽  
Validation Experiment ◽  
Computational Methodology ◽  
Near Wall

A comprehensive study of film cooling on a turbine airfoil leading edge was performed with a documented, well-tested computational methodology. In this paper, numerically predicted heat transfer coefficients on the film-cooled leading edge are compared with experimental data from the open literature. The results are presented as the ratio of heat transfer coefficient with film cooling to that without film cooling, and the physics behind the surface results are discussed. The leading edge model was a half-cylinder in shape with a bluff afterbody to match the validation experiment, and other geometric parameters matched those of Part I of this study. Coolant at a density equal to that of the mainstream flow was injected through three rows of cylindrical film-cooling holes. One row of holes was centered on the stagnation line of the cylinder, and the other two rows were located ±3.5 hole diameters off stagnation. The downstream rows were staggered such that they were centered laterally between holes in the stagnation row. The holes were inclined at 20° with the surface, and made a 90° angle with the streamwise direction (radial injection). Four average blowing ratios were simulated in the range of 0.75 to 1.9, corresponding to the same momentum flux ratios as in Part I of this work. The multi-block, unstructured numerical grid was characterized by high quality and density, especially in the near wall region, in order to minimize error in predictions of the heat transfer. A fully-implicit scheme was used to solve the steady Reynolds-averaged Navier-Stokes equations, and a realizable k-ε model provided turbulence closure. A two-layer near-wall treatment allowed the resolution of the viscous sublayer for maximum accuracy in the prediction of the wall heat transfer coefficient. The numerical predictions exhibited generally good agreement with experimental data. The heat transfer coefficient was observed to increase sharply aft of the holes in the downstream rows. When coupled with the adiabatic effectiveness results of the first paper in this series, it is evident that a systematic computational methodology may be effectively applied to investigate and understand the complicated leading edge film-cooling problem.

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