Abstract
In this paper, a new technique of turbulence generation in large eddy simulation (LES) is studied and verified. In order to generate turbulence similar to the wind tunnel test, the proposed grid inlet technique places the grid on the Inlet boundary to achieve the following effects: changing the grid size controls the turbulence integral length scale and changing the distance from inlet controls the turbulence intensity. The purpose of this paper is to explore the domain requirements of grid-inlet technology by studying the turbulence characteristics of three different grid inlets. In particular, this paper further studies the effects of domain sizes on the lateral correlation of fluctuating wind by arranging the transverse positions of monitoring points irregularly and in equal proportion. Meanwhile, the isotropic hypothesis of gird-generated turbulence is verified by power spectrum. The results show that the turbulence intensity is unaffected by the domain sizes, the larger calculation domain corresponds to the gentler changing trend of the lateral correlation of the fluctuating wind and the flow fields under the three different domain sizes basically satisfy the isotropic hypothesis. The above results are helpful for the further application of the grid inlet technique.
Highlights
Grids are typically used to experimentally generate flows with different turbulence characteristics
The main conclusions of this study are as followed: 1) The turbulence intensity decay rate is unaffected by the domain sizes
2) The turbulence integral scale is proportional to the domain sizes, with a higher a steady value for larger domain size
Summary
Grids are typically used to experimentally generate flows with different turbulence characteristics. Large eddy simulation is the best method to generate turbulence. Pre-computation methods and synthetic inlet methods are the two typical methods to generate turbulence in In Large Eddy Simulation. Because of the time and storage required, this method is not efficient. To let the flow evolve into ‘real’ turbulence, a considerable simulation inlet length was found to be required. DeVilliers [3] describes a more efficient time and data storage method in which internal mapping planes are used to recover flow upstream of the main computational domain. In this method, there is no need to store pre-calculated data. In most pre-computation methods, it is almost impossible to generate turbulence with the specific length scale and turbulence intensity, due to the limitations of boundary layer of the domain geometry
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
