Computational Fluid Dynamics (CFD) methods that are third-order accurate or higher are generally considered high-order methods in the aerospace community. These methods have the potential of yielding accurate CFD solutions in a more efficient manner than first or second-order ones. High-order methods include the popular discontinuous Galerkin (DG) as well as the spectral volume (SV), spectral difference (SD), and PnPm or hybrid DG/finite volume methods. Recently, the flux reconstruction (FR) or correction procedure via reconstruction (CPR) method provides a unifying framework for existing methods including the above mentioned DG, SV, SD as well as new ones with various accuracy and stability properties. This paper provides a review of recent FR/CPR developments together with sample applications and pacing items.
To accomplish NASA missions, it is required to develop advanced aerospace vehicles and operating systems. Since a test-fail-fix approach is very expensive and time consuming for developing advanced vehicles, it has become more economical to utilize computational approaches. Scientists and engineers at NASA Ames Research Center (Ames) began developing computational flow modeling methods for aerodynamic problems as early as the late 1960s. As the high-performance computing technologies advance in conjunction with the NASA Advanced Supercomputing (NAS) facility located at Ames, researchers have made breakthroughs in numerical methods and have performed milestone-setting applications while supporting NASA missions. The current report is intended to present our view on the historical role Ames has played in advancing the computational fluid dynamics (CFD) technology starting from the development of fundamental algorithms and codes for aeronautics leading to the current state-of-the-art flow simulations in support of NASA's aerospace missions.
The paper provides a brief introduction to the near-wall problem of LES and how it can be solved through modeling of the near-wall turbulence. The distinctions and key differences between different approaches are emphasized, both in terms of fidelity (LES, wall-modeled LES, and DES) and in terms of different wall-modeled LES approaches (hybrid LES/RANS and wall-stress-models). The focus is on approaches that model the wall-stress directly, i.e., methods for which the LES equations are formally solved all the way down to the wall. Progress over the last decade is reviewed, and the most important and promising directions for future research are discussed.
Aeronautical and space applications, but more generally various engineering issues, are concerned with noise of high-speed jets. This comprehensive review provides a summary of noise generated by supersonic round jets, including mixing noise, Mach wave radiation, broadband shock-cell noise and screech tones, examines efforts to understand the physics involved, and introduces recent numerical and experimental developments regarding high speed jet noise. It outlines also aerospace applications with topics such as rocket supersonic jet impinging a flame deflector installed on launch pads.