Experimental and Numerical Investigations of Aerodynamic Behavior of a Three-Stage HP-Turbine at Different Operating Conditions

2010 ◽  
Author(s):  
S. A. Abdelfattah ◽  
M. T. Schobeiri
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
High Pressure ◽  
Operating Conditions ◽  
Numerical Investigations ◽  
Turbine Performance ◽  
Speed Range ◽  
Three Stages

This paper describes experimental and numerical investigations of a three-stage high pressure research turbine which incorporates fully 3-D bowed blades at various operating conditions. Experimental data were obtained using interstage aerodynamic measurements at three measurement stations, namely, downstream of the first rotor row, the second stator row and the second rotor row. Measurements were conducted through the use of five-hole probes traversed in both circumferential and radial directions to create a measurement window. Aerodynamics measurements were carried out within a rotational speed range of 1800 to 2800 RPM. Numerical simulation of the aforementioned turbine was performed through the use of a commercial computational fluid dynamics code. A detailed mesh of the three-stages was created and used to simulate the corresponding operating conditions and a comparison was made between experimentally and numerically determined aerodynamics and turbine performance.

Analysis and Modeling of Liquid Holdup in Low Liquid Loading Two-Phase Flow Using Computational Fluid Dynamics and Experimental Data

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Miguel Ballesteros ◽  
Nicolás Ratkovich ◽  
Eduardo Pereyra
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Oil And Gas ◽  
Operating Conditions ◽  
Liquid Holdup ◽  
Liquid Loading ◽  
Two Phase ◽  
Acceptable Error ◽  
Pharmaceutical Industries

Abstract Low liquid loading flow occurs very commonly in the transport of any kind of wet gas, such as in the oil and gas, the food, and the pharmaceutical industries. However, most studies that analyze this type of flow do not cover actual industry fluids and operating conditions. This study focused then on modeling this type of flow in medium-sized (6-in [DN 150] and 10-in [DN 250]) pipes, using computational fluid dynamics (CFD) simulations. When comparing with experimental data from the University of Tulsa, the differences observed between experimental and CFD data for the liquid holdup and the pressure drop seemed to fall within acceptable error, around 20%. Additionally, different pipe sections from a Colombian gas pipeline were simulated with a natural gas-condensate mixture to analyze the effect of pipe inclination and operation variables on liquid holdup, in real industry conditions. It was noticed that downward pipe inclinations favored smooth stratified flow and decreased liquid holdup in an almost linear fashion, while upward inclinations generated unsteady wavy flows, or even a possible annular flow, and increased liquid holdup and liquid entrainment into the gas phase.

scholarly journals Numerical investigations on effect of wear-ring clearance on performance of a submersible well pump

2017 ◽  
Vol 9 (7) ◽  
pp. 168781401770415 ◽  
Author(s):  
Weidong Shi ◽  
Xiongfa Gao ◽  
Qihua Zhang ◽  
Desheng Zhang ◽  
Daoxing Ye
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Reverse Flow ◽  
Internal Flow ◽  
Experimental Results ◽  
Ring Size ◽  
Numerical Investigations ◽  
Calculation Results

A typical submersible well pump was investigated in this article. The whole flow field of submersible well pump was numerically simulated by computational fluid dynamics software. The influence of clearance of wear-rings on the external characteristic and internal flow field was analyzed through comparing the calculation results with experimental results. The result of the numerical simulation shows that changing clearance of front wear-ring has a greater impact on pump performances than changing clearance of back wear-ring, and the head and efficiency of pump decrease with the increase in the size of clearance. Especially when the size of clearance is larger than 0.5 mm, decreasing becomes more obvious. When the front and back wear-ring size of the clearance comes to 1.0 mm, the efficiency decreases from the highest point of 75.31% to 65.44% at rated flow, and the head of pump decreases about 3.5 m. When the size of clearance is 0.2 mm, reverse-flow will appear in the front shroud cavity of the impeller, and leakage from back wear-ring through the balance hole into the impeller, which has a little influence on the flow field of the impeller inlet.

scholarly journals Numerical Simulation of Flow in Parshall Flume Using Selected Nonlinear Turbulence Models

Hydrology ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 151
Author(s):  
Mehdi Heyrani ◽  
Abdolmajid Mohammadian ◽  
Ioan Nistor
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Standard Error ◽  
Physical Modeling ◽  
Hydraulic Structure ◽  
Turbulence Models ◽  
Computational Fluid Dynamics Cfd ◽  
The Right

This study uses a computational fluid dynamics (CFD) approach to simulate flows in Parshall flumes, which are used to measure flowrates in channels. The numerical results are compared with the experimental data, which show that choosing the right turbulence model, e.g., v2−f and LC, is the key element in accurately simulating Parshall flumes. The Standard Error of Estimate (SEE) values were very low, i.e., 0.76% and 1.00%, respectively, for the two models mentioned above. The Parshall flume used for this experiment is a good example of a hydraulic structure for which the design can be more improved by implementing a CFD approach compared with a laboratory (physical) modeling approach, which is often costly and time-consuming.

scholarly journals Modeling of H2 Permeation through Electroless Pore-Plated Composite Pd Membranes Using Computational Fluid Dynamics

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 123
Author(s):  
Alberto Fernández ◽  
Cintia Casado ◽  
David Alique ◽  
José Antonio Calles ◽  
Javier Marugán
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Hydrogen Permeation ◽  
Membrane Surface ◽  
Molar Fraction ◽  
Operating Conditions ◽  
Cfd Modeling ◽  
Wide Range ◽  
The Impact

This work focused on the computational fluid dynamics (CFD) modeling of H2/N2 separation in a membrane permeator module containing a supported dense Pd-based membrane that was prepared using electroless pore-plating (ELP-PP). An easy-to-implement model was developed based on a source–sink pair formulation of the species transport and continuity equations. The model also included the Darcy–Forcheimer formulation for modeling the porous stainless steel (PSS) membrane support and Sieverts’ law for computing the H2 permeation flow through the dense palladium film. Two different reactor configurations were studied, which involved varying the hydrogen flow permeation direction (in–out or out–in). A wide range of experimental data was simulated by considering the impact of the operating conditions on the H2 separation, such as the feed pressure and the H2 concentration in the inlet stream. Simulations of the membrane permeator device showed an excellent agreement between the predicted and experimental data (measured as permeate and retentate flows and H2 separation). Molar fraction profiles inside the permeator device for both configurations showed that concentration polarization near the membrane surface was not a limit for the hydrogen permeation but could be useful information for membrane reactor design, as it showed the optimal length of the reactor.

Computational Fluid Dynamics Analysis of a Hydrokinetic Turbine Based on Oscillating Hydrofoils

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Thomas Kinsey ◽  
Guy Dumas
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Numerical Simulations ◽  
Spatial Configuration ◽  
Operating Conditions ◽  
Power Extraction ◽  
Numerical Predictions ◽  
Hydrokinetic Turbine ◽  
Computational Fluid Dynamics Analysis

The performance of a new concept of hydrokinetic turbine using oscillating hydrofoils to extract energy from water currents (tidal or gravitational) is investigated using URANS numerical simulations. The numerical predictions are compared with experimental data from a 2 kW prototype, composed of two rectangular oscillating hydrofoils of aspect ratio 7 in a tandem spatial configuration. 3D computational fluid dynamics (CFD) predictions are found to compare favorably with experimental data especially for the case of a single-hydrofoil turbine. The validity of approximating the actual arc-circle trajectory of each hydrofoil by an idealized vertical plunging motion is also addressed by numerical simulations. Furthermore, a sensitivity study of the turbine’s performance in relation to fluctuating operating conditions is performed by feeding the simulations with the actual time-varying experimentally recorded conditions. It is found that cycle-averaged values, as the power-extraction efficiency, are little sensitive to perturbations in the foil kinematics and upstream velocity.

scholarly journals Computational fluid dynamics analysis of a high-throughput viscous heater to process feces and a fecal simulant using temperature and shear rate-dependent viscosity model

2017 ◽  
Vol 8 (1) ◽  
pp. 27-32
Author(s):  
C. L. German ◽  
J. T. Podichetty ◽  
A. Muzhingi ◽  
B. Makununika ◽  
J. Smay ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Shear Rate ◽  
Operating Conditions ◽  
Rate Dependent ◽  
Annular Gap ◽  
Computational Fluid Dynamics Analysis ◽  
Fecal Sludge ◽  
Dependent Viscosity

Abstract Open defecation and poor fecal management facilitates the spread of disease. Viscous heating can pasteurize fecal sludge by creating a high shear field in the annular gap between a stationary, cylindrical outer shell and a rotating inner core. As sludge flows axially through the annular gap, thorough mixing and frictional heating eliminate cool spots where microbes may survive. A viscous heater (VH) compares favorably to a conventional heat exchanger, where cool slugs may occur. Computational fluid dynamics (CFD) was used to determine the effects of geometry and fluid rheology on VH performance over a range of conditions. A shear-rate and temperature-dependent rheological model was developed from experimental data, using a sludge simulant. CFD of an existing VH used the model to improve the original naïve design by including temperature and shear rate-dependent viscosity. CFD results were compared to experimental data at 132 and 200 L/hr to predict design and operating conditions for 1,000 L/hr. Subsequent experimentation with fecal sludge indicated that the CFD approach was valid for design and operation.

Validation of a comprehensive computational fluid dynamics methodology to predict the direct injection process of gasoline sprays using Spray G experimental data

2019 ◽  
Vol 21 (1) ◽  
pp. 199-216 ◽  
Author(s):  
Davide Paredi ◽  
Tommaso Lucchini ◽  
Gianluca D’Errico ◽  
Angelo Onorati ◽  
Lyle Pickett ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Liquid Velocity ◽  
Direct Injection ◽  
Combustion Process ◽  
Operating Conditions ◽  
Gasoline Direct Injection ◽  
Injection Process ◽  
Dynamics Simulations

A detailed prediction of injection and air–fuel mixing is fundamental in modern direct injection, spark-ignition engines to guarantee a stable and efficient combustion process and to minimize pollutant formation. Within this context, computational fluid dynamics simulations nowadays represent a powerful tool to understand the in-cylinder evolution of spray and air–fuel charge. To guarantee the accuracy of the adopted multidimensional spray sub-models, it is mandatory to validate the computed results against available experimental data under well-defined operating conditions. To this end, in this work, the authors proposed the calibration and validation of a comprehensive set of spray sub-models by means of the simulation of the Spray G experiment, available in the context of the engine combustion network. For a suitable validation of the proposed numerical setup in addition to the baseline condition, gasoline direct injection operating points typical of early injection with homogeneous operation, late injection with high ambient density and flash boiling with enhanced fuel evaporation were also simulated. Numerical computations were validated against a wide set of available experimental data by means of an accurate post-processing analysis taking into account axial liquid and vapor penetrations, gas-phase velocity between spray plumes, droplet size, plume liquid velocity, direction and mass distribution. Satisfactory results were achieved with the proposed setup, which is able to predict gasoline spray evolution under different operating conditions.

scholarly journals Computational Fluid Dynamics Investigation of a Core-Mounted Target-Type Thrust Reverser—Part 2: Reverser Deployed Configuration

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Tashfeen Mahmood ◽  
Anthony Jackson ◽  
Vishal Sethi ◽  
Bidur Khanal ◽  
Fakhre Ali
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Sea Level ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
Target Type ◽  
Performance Criteria ◽  
Static Conditions ◽  
Thrust Reverser

Core-mounted target-type thrust reverser (CMTTTR) design was proposed by NASA in the second half of the 90 s. NASA carried out several experiments at static conditions, and their acquired results suggested that the performance characteristics of the CMTTTR design fall short to comply with the mandatory thrust reverser (TR) performance criteria, and were therefore regarded as an infeasible design. However, the authors of this paper believe that the results presented by NASA for the CMTTTR design require further exploration to facilitate the complete understanding of its true performance potential. This part 2 paper is a continuation from Part 1 (reverser stowed configuration) and presents a comprehensive three-dimensional (3D) computational fluid dynamics (CFD) analyses of the CMTTTR in deployed configuration. The acquired results are extensively analyzed for aforementioned TR configuration operating under the static operating conditions at sea level, i.e., sea-level static, International Standard Atmosphere (ISA); the analyses at forward flight conditions will be covered in part 3. The key objectives of this paper are: First, to validate the acquired CFD results with the experimental data provided by NASA; this is achieved by measuring the static pressure values on various surfaces of the deployed CMTTTR model. The second objective is to estimate the performance characteristics of the CMTTTR design and corroborate the results with experimental data. The third objective is to estimate the pressure thrust (i.e., axial thrust generated due to the pressure difference across various reverser surfaces) and discuss its significance for formulating the performance of any TR design. The fourth objective is to investigate the influence of kicker plate installation on overall TR performance. The fifth and final objective is to examine and discuss the overall flow physics associated with the thrust reverse under deployed configuration.

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