A Filtering Method For Gravitationally Stratified Flows

Technical Report · Mon Apr 25 00:00:00 EDT 2005

DOI:https://doi.org/10.2172/922835· OSTI ID:922835

Gatti-Bono, Caroline; Colella, Phillip

Gravity waves arise in gravitationally stratified compressible flows at low Mach and Froude numbers. These waves can have a negligible influence on the overall dynamics of the fluid but, for numerical methods where the acoustic waves are treated implicitly, they impose a significant restriction on the time step. A way to alleviate this restriction is to filter out the modes corresponding to the fastest gravity waves so that a larger time step can be used. This paper presents a filtering strategy of the fully compressible equations based on normal mode analysis that is used throughout the simulation to compute the fast dynamics and that is able to damp only fast gravity modes.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Director. Office of Science. Advanced ScientificComputing Research
• DOE Contract Number: DE-AC02-05CH11231
• OSTI ID: 922835
• Report Number(s): LBNL-57161; R&D Project: 619501; BnR: KJ0101010; TRN: US200806%%325
• Country of Publication: United States
• Language: English

Related Subjects

99
ACOUSTICS
COMPRESSIBLE FLOW
FROUDE NUMBER
GRAVITY WAVES
NORMAL-MODE ANALYSIS
SIMULATION