scholarly journals CFD Analysis of C-D Nozzle Compared with Theoretical & Experimental Data

2018 ◽  
Vol 10 (2) ◽  
pp. 53-64
Author(s):  
KEIR Stewart ◽  
◽  
IVES Rob ◽  
HAMAD Faik ◽  
◽  
...  
Keyword(s):  
Experimental Data ◽  
Cfd Analysis

Hybrid Analysis of Gas Annular Seals With Energy Equation

2013 ◽  
Author(s):  
Patrick J. Migliorini ◽  
Alexandrina Untaroiu ◽  
William C. Witt ◽  
Neal R. Morgan ◽  
Houston G. Wood
Keyword(s):  
Experimental Data ◽  
Hybrid Method ◽  
Energy Equation ◽  
Flow Analysis ◽  
Experimental Studies ◽  
Rotor System ◽  
Bulk Flow ◽  
Outlet Temperature ◽  
Cfd Analysis ◽  
Annular Seals

Annular seals are used in turbomachinery to reduce secondary flow between regions of high and low pressure. In a vibrating rotor system, the non-axisymmetric pressure field developed in the small clearance between the rotor and the seal generate reactionary forces that can affect the stability of the entire rotor system. Traditionally, two analyses have been used to study the fluid flow in seals, bulk-flow analysis and computational fluid dynamics (CFD). Bulk-flow methods are computational inexpensive, but solve simplified equations that rely on empirically derived coefficients and are moderately accurate. CFD analyses generally provide more accurate results than bulk-flow codes, but solution time can vary between days and weeks. For gas damper seals, these analyses have been developed with the assumption that the flow can be treated as isothermal. Some experimental studies show that the difference between the inlet and outlet temperature temperatures is less than 5% but initial CFD studies show that there can be a significant temperature change which can have an effect on the density field. Thus, a comprehensive analysis requires the solution of an energy equation. Recently, a new hybrid method that employs a CFD analysis for the base state, unperturbed flow and a bulk-flow analysis for the first order, perturbed flow has been developed. This method has shown to compare well with full CFD analysis and experimental data while being computationally efficient. In this study, the previously developed hybrid method is extended to include the effects of non-isothermal flow. The hybrid method with energy equation is then compared with the isothermal hybrid method and experimental data for several test cases of hole-pattern seals and the importance of the use of energy equation is studied.

Assessment of CFD Approaches for Next-Generation Combustor Design

2014 ◽  
Author(s):  
Kumud Ajmani ◽  
Hukam C. Mongia ◽  
Phil Lee
Keyword(s):  
Experimental Data ◽  
Direct Injection ◽  
Operating Conditions ◽  
Reacting Flow ◽  
Cfd Analysis ◽  
Next Generation ◽  
Lean Direct Injection ◽  
Liquid Spray ◽  
Exit Temperature ◽  
Computational Predictions

An effort was undertaken to perform CFD analysis of fluid flow in Lean-Direct Injection (LDI) combustors with axial swirl-venturi elements for next-generation LDI-2 design. The National Combustion Code (NCC) developed at NASA Glenn Research Center was used to perform reacting flow computations on an LDI-2 combustor configuration with thirteen injector elements arranged in four fuel stages. Reacting computations were performed with a consistent approach for mesh-optimization, liquid spray modeling and kinetics modeling. Computational predictions of Emissions Index (EINOx) and combustor exit temperature were compared with two sets of experimental data at medium and high-power operating conditions, for two different pressure-drop conditions in the combustor. The NCC simulations predicted the combustor exit temperature to within 1–2% of experimental data. The accuracy of the EINOx predictions from the NCC simulations was within 10% to 30% of experimental data.

Computational and Experimental Comparison of Different Volute Geometries in a Radial Compressor

2000 ◽  
Author(s):  
Arttu Reunanen ◽  
Harri Pitkänen ◽  
Timo Siikonen ◽  
Harri Heiska ◽  
Jaakko Larjola ◽  
...  
Keyword(s):  
Experimental Data ◽  
Time Dependent ◽  
Experimental Comparison ◽  
Cfd Analysis ◽  
Laboratory Measurements ◽  
Radial Compressor ◽  
Sliding Mesh ◽  
Overall Performance ◽  
Operating Points ◽  
Mesh Technique

Two different volute geometries of a radial compressor at three different operating points have been analyzed using Computational Fluid Dynamics and detailed laboratory measurements. The performance of the volutes were compared using steady-state CFD-analysis, where the volute and the impeller with diffuser were modeled separately. In addition, a time dependent simulation of the complete compressor using the sliding mesh technique was performed for one operation point. Both volutes were manufactured and the overall performance of the compressor, the pressure distribution in the volute and the flow field in the volute inlet were measured with the respective volute geometries. The results obtained from steady, quasi-steady and time-accurate simulations are compared with experimental data.

Numerical Modelling in Turbines for OWC Systems: Application to a Radial Impulse

2010 ◽  
Author(s):  
Juan G. Gonza´lez ◽  
Bruno Pereiras ◽  
Francisco Castro ◽  
Miguel A. Rodri´guez
Keyword(s):  
Experimental Data ◽  
Numerical Modelling ◽  
Cfd Analysis ◽  
Oscillating Water Column ◽  
Impulse Turbine ◽  
One Dimensional ◽  
Directional Flow ◽  
Axial Turbines ◽  
D Model ◽  
Reaction Degree

This work is focused on radial impulse turbines for an Oscillating Water Column (OWC) which is one of the alternatives to the Wells turbines traditionally installed in the OWC systems. All self-rectifying turbines work under special conditions due to the bi-directional flow caused by OWC. But a radial impulse turbine has another special point: it works alternatively as an inflow/outflow turbine, so that its behavior is not symmetrical as is expected in axial turbines for OWC (Wells and axial impulse turbines). The complete CFD analysis we have made of a radial impulse turbine is described. The model was created for a specific turbine but can be adapted for any self-rectifying turbine. We have studied the turbine by means of a one-dimensional study and a 3-D model solved with FLUENT® software, and the results were validated with experimental data extracted from the bibliography. This model allowed us to analyse both the classical dimensionless parameters and the flow pattern. Moreover, we have introduced a special definition for the reaction degree in order to analyse the process of the energy conversion.

ICONE19-43590 Evaluation of supercritical CO_2 centrifugal compressor experimental data by CFD analysis

2011 ◽  
Vol 2011.19 (0) ◽  
pp. _ICONE1943-_ICONE1943
Author(s):  
Kazuhisa TAKAGI ◽  
Yasushi MUTO ◽  
Takao ISHIZUKA ◽  
Noriyuki WATANABE ◽  
Masanori ARITOMI
Keyword(s):  
Experimental Data ◽  
Centrifugal Compressor ◽  
Cfd Analysis

Aerodynamic Performance Prediction of a Profile in Ground Effect

2014 ◽  
Author(s):  
Carlo Cravero
Keyword(s):  
Experimental Data ◽  
Performance Prediction ◽  
Reference Data ◽  
Ground Effect ◽  
Aerodynamic Performance ◽  
The Other ◽  
Cfd Analysis ◽  
Suction Surface ◽  
Source Codes ◽  
Commercial Code

A very detailed experimental case of a reversed profile in ground effect has been selected in the open literature and the available experimental data have been used as reference data for CFD analysis. The CFD approach has been used to predict the aerodynamic performance of the profile at different heights with respect to the ground: from the freestream case (no ground effect) to a low height where the stall on the suction surface limits the profile operation. Different CFD codes have been used starting with a well-known commercial code to different open source codes. The set of analysis with the commercial code has allowed the setup of the mesh to have the best accuracy from the simulations. The same grids have been used for the other codes in order to directly compare the solver properties without mesh influence. The results obtained by the codes are compared and discussed.

The Development of Low-NOx CLEAN Combustor in the Frame of EEFAE Research Program

2007 ◽  
Author(s):  
Salvatore Colantuoni ◽  
Pasquale Di Martino ◽  
Giuseppe Cinque ◽  
Alessandro Terlizzi
Keyword(s):  
Experimental Data ◽  
Research Program ◽  
Environmentally Friendly ◽  
Cfd Analysis ◽  
European Research ◽  
A Posteriori ◽  
Test Rig ◽  
Comprehensive Understanding ◽  
Combustion Performance ◽  
Aero Engine

In the frame of the European Research Program EEFAE (Efficient and Environmentally Friendly Aero-Engine) successfully completed in five years (2000-2005), an advanced low-NOx combustor has been designed and validated for the CLEAN (Component vaLidator for Environmentally-friendly Aero-eNgine) demonstrator. The objectives of the paper are to show an overview of the CLEAN combustor development, such as combustor design, manufacturing and test rig results, and to provide first comparison between a-posteriori CFD analysis Vs. Rig experimental data, useful for a more comprehensive understanding of combustion performance.

Model Testing and CFD Analysis of 2D Profiles Towards Offshore Applications

2013 ◽  
Author(s):  
Lucas do Vale Machado ◽  
Antonio Carlos Fernandes ◽  
Gustavo César Rachid Bodstein
Keyword(s):  
Experimental Data ◽  
Experimental Measurements ◽  
Cfd Analysis ◽  
Two Dimensional ◽  
Reference Simulation ◽  
Sst Turbulence Model ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Naca 0015 ◽  
Good Agreement

In this paper we present numerical and experimental work motivated by the study of a rudder profile with significant levels of lift that provides better performance for the maneuvering and stabilization of a ship. This is the so-called Schilling profile. The analysis of the two-dimensional subsonic steady flow over four profiles was carried out using computational fluid dynamics (CFD) tools with a κ-ω SST turbulence model. We consider three Schilling profiles with different thicknesses and the classical NACA 0015 profile, taken as a reference. Simulation results were compared to our experimental measurements at various angles of attack and two orders of magnitude of the Reynolds number, 5.45 × 104 and 1.09 × 105. The numerical results show general good agreement with experimental data and highlight the distinct behavior of Schilling profile.

scholarly journals CFD Analysis of Marine Propeller Configurations in Cavitating Conditions

2020 ◽  
Vol 3 (3) ◽  
pp. 251-264
Author(s):  
Ante Sikirica ◽  
Ivana Lučin ◽  
Zoran Čarija ◽  
Bože Lučin
Keyword(s):  
Experimental Data ◽  
Real World ◽  
Cavitating Flow ◽  
Performance Characteristics ◽  
Cfd Analysis ◽  
Marine Propeller ◽  
Performance Differences

Diversely performing propellers as a consequence of design variability are nowadays a commonplace. Fundamental geometric particularities, including size, stipulate performance characteristics, which are usually the only required parameters when deciding on a propeller for specific purpose. With the main focus on the performance, accompanying phenomena, e.g. cavitation, tend to be overlooked. In this paper, propeller configurations in cavitating flow are investigated, with emphasis on real-world performance differences caused by cavitation. Recommended CFD approach is presented with respect to configuration specifics. Available experimental data is used as a baseline for a single propeller, which is then analysed in ducted and tandem configurations with resulting cavitation extents and shape evaluated in the context of current designs.

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