Acoustic damping for explicit calculations of fluid flow at low Mach number

PDF Version Also Available for Download.

Description

A method is proposed for damping the sound waves in explicit calculations of fluid flow at low Mach number, where sound waves are usually not of interest but may distract attention from other flow features. The method is based on the introduction of an artificial pressure q of the form q = - q/sub 0/rhoc/sup 2/..delta..t(del x u - del x u/sub 0/), where q/sub 0/ is a coefficient of order unity, rho is the density, c is the sound speed, ..delta..t is the time step, and u/sub 0/ is the velocity field that would obtain at zero Mach number. ... continued below

Physical Description

Pages: 15

Creation Information

Ramshaw, J.D.; O'Rourke, P.J. & Amsden, A.A. January 1, 1986.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

A method is proposed for damping the sound waves in explicit calculations of fluid flow at low Mach number, where sound waves are usually not of interest but may distract attention from other flow features. The method is based on the introduction of an artificial pressure q of the form q = - q/sub 0/rhoc/sup 2/..delta..t(del x u - del x u/sub 0/), where q/sub 0/ is a coefficient of order unity, rho is the density, c is the sound speed, ..delta..t is the time step, and u/sub 0/ is the velocity field that would obtain at zero Mach number. When del x u/sub 0/ is zero, the method becomes equivalent to the use of an artificial bulk viscosity q/sub 0/rhoc/sup 2/..delta..t. However, del x u/sub 0/ can be substantially different from zero in problems with heat or mass sources (e.g., combustion), and its inclusion is then essential to obtain the correct pressure field. The method is well suited for use in conjunction with explicit numerical schemes that employ acoustic subcycling or artificial reduction of the sound speed for improved efficiency at low Mach number. The beneficial effects of the method are illustrated by means of calculations with an acoustic subcycling computer program. 9 refs., 1 fig.

Physical Description

Pages: 15

Notes

NTIS, PC A02/MF A01; 1.

Source

  • Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Other: DE86007576
  • Report No.: LA-10641-MS
  • Grant Number: W-7405-ENG-36
  • DOI: 10.2172/6100813 | External Link
  • Office of Scientific & Technical Information Report Number: 6100813
  • Archival Resource Key: ark:/67531/metadc1105625

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • January 1, 1986

Added to The UNT Digital Library

  • Feb. 22, 2018, 7:45 p.m.

Description Last Updated

  • May 11, 2018, 11:15 a.m.

Usage Statistics

When was this report last used?

Congratulations! It looks like you are the first person to view this item online.

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Ramshaw, J.D.; O'Rourke, P.J. & Amsden, A.A. Acoustic damping for explicit calculations of fluid flow at low Mach number, report, January 1, 1986; New Mexico. (digital.library.unt.edu/ark:/67531/metadc1105625/: accessed July 16, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.