scholarly journals Advancement of Turbine Aerodynamic Design Techniques

Author(s):  
Lisa W. Griffin ◽  
Frank W. Huber

The Consortium for Computational Fluid Dynamics (CFD) Application in Propulsion Technology has been created at NASA/MSFC. Its purpose is to advance the state-of-the-art of CFD technology, to validate CFD codes and models, and to demonstrate the benefits attainable through the application of CFD in component design. Three teams are currently active within the Consortium: (1) the Turbine Technology Team, (2) the Pump Stage Technology Team, and (3) the Combustion Devices Technology Team. The goals, dynamics, and activities of the Turbine Team are the subjects of this paper. The Consortium is managed by NASA. The Turbine Team is co-coordinated by a NASA representative from the CFD area and an industry (Pratt & Whitney) representative from the area of turbine aerodynamic design. Membership of the Turbine Team includes experts in design, analysis, and testing from the government, industry, and academia. Each member brings a unique perspective, expertise, and experience to bear on the team’s goals of improving turbine efficiency and robustness while reducing the amount of developmental testing. To this end, an advanced turbine concept has been developed within the team using CFD as an integral part of the design process. This concept employs unconventionally high turning blades and is predicted to provide cost and performance benefits over traditional designs. This concept will be tested in the MSFC Turbine Airflow Facility to verify the design and to provide a unique set of data for CFD code validation. Currently, the team is developing and analyzing methods to reduce secondary and tip losses to further enhance turbine efficiency. The team has also targeted volute development as an area that could benefit from detailed CFD analysis.

2016 ◽  
Vol 819 ◽  
pp. 356-360
Author(s):  
Mazharul Islam ◽  
Jiří Fürst ◽  
David Wood ◽  
Farid Nasir Ani

In order to evaluate the performance of airfoils with computational fluid dynamics (CFD) tools, modelling of transitional region in the boundary layer is very critical. Currently, there are several classes of transition-based turbulence model which are based on different methods. Among these, the k-kL- ω, which is a three equation turbulence model, is one of the prominent ones which is based on the concept of laminar kinetic energy. This model is phenomenological and has several advantageous features. Over the years, different researchers have attempted to modify the original version which was proposed by Walter and Cokljat in 2008 to enrich the modelling capability. In this article, a modified form of k-kL-ω transitional turbulence model has been used with the help of OpenFOAM for an investigative CFD analysis of a NACA 4-digit airfoil at range of angles of attack.


2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Jianjiao Jin ◽  
Jianfeng Pan ◽  
Zhigang Lu ◽  
Qingrui Wu ◽  
Lizhong Xu ◽  
...  

Abstract In this paper, a novel one-dimensional matching method of an asymmetric twin-scroll turbine (ATST) with a small scroll bypass wastegate is initially presented for energy improvement. The developed method presents further insights into efficiency prediction of the ATST and the small scroll exhaust bypass in the matching process of model characterization. The efficiency of the small and large scroll turbines was approximately assessed with two times flow parameters of the small and large scroll turbines, respectively, as well as according to turbine efficiency prediction curves. Subsequently, given the matching results of a 9-L engine, a targeted ATST was developed; its effectiveness was verified by computational fluid dynamics (CFD) and the performance tests of a turbine and an engine. As revealed from the results, the prediction efficiency of the ATST well complies with that of the numerical calculation and performance tests of turbines and engines. Compared with the common large scroll exhaust bypass wastegate, the small one exhibits better engine performance and can save nearly 0.5–1.5% fuel consumption at middle and high engine speeds. Moreover, the reasons of which were explored for better understanding of the mechanism accordingly.


2003 ◽  
Author(s):  
Bassam Abu-Hijleh ◽  
Jiyuan Tu ◽  
Aleksander Subic ◽  
Huafeng Li ◽  
Katherine Ilie

The performance of a Rotor-Casing Assembly is influenced more by the internal air leakages than by any other thermo-fluid aspect of its behaviour. The pressure difference driving the air along a leakage path varies periodically and does so in a manner that may not be the same for every leakage path. So the distribution of leakage through the various leakage paths within the machine is important for the improvement of its performance. The total volume of air leakage and the distribution of the leakage among the different paths depend on the rotor-rotor and rotor-casing clearances as well as the geometry of the rotors’ lobes. Computational Fluid Dynamics (CFD) analysis was carried out using the FLUENT. Geometry definition, mesh generation, boundary and flow conditions, and solver parameters have all been investigated as the part of the numerical analysis. This analysis was conducted for static rotors at different positions. The results indicate that the size of the clearances as well as the geometry of the rotors’ lobes can have a significant effect on the total volume of the air leakage as well as the distribution of the leakage among the three main leakage paths. The results can be used to ascertain the proper levels of clearances to be used and the best rotor lobes geometry to be used for the practical reduction of air leakage.


2018 ◽  
Vol 7 (4.13) ◽  
pp. 202-204
Author(s):  
Mahadhir A Rahman ◽  
Mohammad Yazdi Harmin ◽  
Mohd Fuad Koslan ◽  
Mohd Rashdan Saad ◽  
Mohd Faisal Abdul Hamid

This paper presents the investigation of aerodynamic performance of inboard Store-X and Store-Y configurations on the X-plane aircraft model through computational fluid dynamics (CFD) analysis. The X-plane and Store-Y represent the default store and pylon integration while Store-X provides a possibility for other types of store to be integrated. These stores are loosely based upon the two most commonly used by the western and eastern blocks. The resultant lift, drag and moment forces are of interest in order to observe their impact with respect to the two different stores configurations. The finding shows that the aerodynamic impact with respect to Store-X installation on the inboard pylon station is insignificant when compared to default system, hence offers the safety of delivering the Store-X from the X-plane aircraft.


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