Standard test case for a low-speed, turbulent junction vortex flow

AIAA Journal ◽  
1991 ◽  
Vol 29 (1) ◽  
pp. 14-15 ◽  
Author(s):  
F. J. Pierce
Keyword(s):  
Vortex Flow ◽  
Standard Test ◽  
Test Case ◽  
Low Speed

scholarly journals Evaluation of a Scale-Resolving Methodology for the Multidimensional Simulation of GDI Sprays

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2699 ◽  
Author(s):  
Giovanni Di Ilio ◽  
Vesselin K. Krastev ◽  
Giacomo Falcucci
Keyword(s):  
Turbulence Modeling ◽  
Direct Injection ◽  
Test Procedure ◽  
Hybrid Approach ◽  
Development Trend ◽  
Standard Test ◽  
Gasoline Direct Injection ◽  
Model Parameters ◽  
Test Case ◽  
Passenger Cars

The introduction of new emissions tests in real driving conditions (Real Driving Emissions—RDE) as well as of improved harmonized laboratory tests (World Harmonised Light Vehicle Test Procedure—WLTP) is going to dramatically cut down NOx and particulate matter emissions for new car models that are intended to be fully Euro 6d compliant from 2020 onwards. Due to the technical challenges related to exhaust gases’ aftertreatment in small-size diesel engines, the current powertrain development trend for light passenger cars is shifted towards the application of different degrees of electrification to highly optimized gasoline direct injection (GDI) engines. As such, the importance of reliable multidimensional computational tools for GDI engine optimization is rapidly increasing. In the present paper, we assess a hybrid scale-resolving turbulence modeling technique for GDI fuel spray simulation, based on the Engine Combustion Network “Spray G” standard test case. Aspects such as the comparison with Reynolds-averaged methods and the sensitivity to the spray model parameters are discussed, and strengths and uncertainties of the analyzed hybrid approach are pointed out. The outcomes of this study serve as a basis for the evaluation of scale-resolving turbulence modeling options for the development of next-generation directly injected thermal engines.

Low-Speed Wall Interference Assessment/Correction with Vortex Flow Effect

1997 ◽  
Vol 34 (2) ◽  
pp. 220-227 ◽  
Author(s):  
Ching-Chyuan A. Hsing ◽  
C. Edward Lan
Keyword(s):  
Vortex Flow ◽  
Flow Effect ◽  
Low Speed

A Generalized Axisymmetric Boundary Condition Method for Parallel Unstructured Field Solvers

2010 ◽  
Author(s):  
Daniel G. Hyams ◽  
Robert Webster ◽  
Kidambi Sreenivas
Keyword(s):  
Boundary Condition ◽  
Search Algorithm ◽  
Pressure Ratio ◽  
Standard Test ◽  
Test Case ◽  
Parallel Mechanisms ◽  
Client Data ◽  
Boundary Condition Method ◽  
Design Speed ◽  
Control Volumes

A generalized interpolative interface is developed to provide an axisymmetric boundary condition for multielement unstructured field solvers, including those that require highly stretched anisotropic meshes. The method centers around an extruded interpolative interface that does not require matched unstructured grids on the corresponding axisymmetric surfaces. Arc-based mesh extrusions are constructed from each periodic interface, which allow for closure and the solution of control volumes that lie on the interface. For each extruded point, a corresponding virtual point is created in order to control the exact location at which the client data interpolations are performed; for axisymmetric surfaces, the virtual points are rotated and placed inside of the opposite side of the domain. Special procedures, such as utilization of surface projections and parallel boundary layer displacement algorithms, are required for support of highly stretched anisotropic grids commonly used in the resolution of boundary layers in fluid flow solvers. All algorithms used to extrude the interpolative surface, place virtual points, and interpolate for the client data must be parallelized for compatibility with modern parallel field solvers. No restrictions are to be placed on the subdomain decomposition. To this end, fully general parallel mechanisms are implemented in order to transport data from its native storage to a possibly remote location. This overall axisymmetric boundary condition scheme is implemented in the Tenasi code for testing. Interpolation requires a parallel unstructured multielement search algorithm, which is a concerted effort by itself, and is the subject of an upcoming paper. This axisymmetric interface scheme is validated on an empty rotor passage, as well as on a Rotor 37 standard test case at full design speed. For these simulations, the two equation Menter SST [1] turbulence model is utilized. Profiles of the relative Mach number aft of the blade and pressure ratio data match very well with experimental results, demonstrating the validity of the proposed approach.

scholarly journals Simulations of Aeroelasticity in an Annular Cascade Using a Parallel 3-Dimensional Navier-Stokes Solver

2002 ◽  
Author(s):  
Ivan McBean ◽  
Feng Liu ◽  
Kerry Hourigan ◽  
Mark Thompson
Keyword(s):  
Unsteady Flow ◽  
Flow Model ◽  
Standard Test ◽  
Navier Stokes ◽  
Test Case ◽  
Turbine Cascade ◽  
3 Dimensional ◽  
Flow Through ◽  
The Stability ◽  
Annular Cascade

A parallel multi-block Navier-Stokes solver with the k-ω turbulence model is developed to simulate the 3-dimensional unsteady flow through an annular turbine cascade. Results at mid-span are compared with the experimental results of Standard Test Case 4. Comparisons are made between 3-dimensional and 2-dimensional, and inviscid and viscous simulations. The inclusion of a viscous flow model does not greatly affect the stability of the configuration.

Optimization of Non-axisymmetric Endwall Contours for the Rotor of a Low Speed, 112-Stage Research Turbine With Unshrouded Blades—Optimization and Experimental Validation

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Jonathan Bergh ◽  
Glen Snedden ◽  
Dwain Dunn
Keyword(s):  
Experimental Results ◽  
Pressure Probe ◽  
Test Case ◽  
Current Case ◽  
Low Speed ◽  
Additional Information ◽  
Measurement Plane ◽  
Direct Laser ◽  
Improved Performance ◽  
Design And Practice

Abstract This paper presents the predicted, as well as final experimental results for the design of an automatically optimized non-axisymmetric endwall and as such, attempts to close the loop between design and practice, providing additional information to other groups involved in the design of endwall contours. The contours designed in this investigation were manufactured using the direct laser sintering rapid prototyping method and installed and tested in the low-speed, 112-stage turbine at the CSIR’s test turbine facility (TTF) in Pretoria, South Africa. Steady-state 5-hole pressure probe traverses were used to characterize the performance and flow profiles upstream, immediately downstream and in a quasi-“mixed-out” sense downstream of the rotor. In addition to the datum (annular) case, both the computed as well as experimental results were compared to the corresponding results generated for a “generically” contoured rotor which was originally designed for a linear cascade test case, but one which used the same blade profile to the current case. The results show that in general both sets of contours performed well, although the added emphasis on flow correction for the contours produced in this investigation resulted in slightly worse performance in terms of loss at the rotor exit (X3) but greatly improved performance in terms of the efficiency and flow angles at the “mixed-out” (X4) measurement plane.

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