Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): S. Scesa; F. M. Sauer
    Date: 1954
    Source: Tech. Pap. 12. Berkeley, CA: U.S. Department of Agriculture, Forest Service, California Forest and Range Experiment Station. 47 p.
    Publication Series: Technical Paper
    Station: Pacific Southwest Research Station
    PDF: Download Publication  (7.0 MB)


    The transfer theory is applied to the problem of atmospheric diffusion of momentum and heat induced by line and point sources of heat on the surface of the earth. In order that the validity of the approximations of the boundary layer theory be realized, the thickness of the layer in which the temperatures and velocities differ appreciably from the values at infinity must be small compared to the height of the region of influence. Variations of four dependent variables--inflow rate, inflow velocities, maximum velocities, and maximum temperature--as a function of elevation for representative heat source strengths are compared for the four cases investigated. In addition, the shape of the region of influence and the factors affecting the shape are investigated.

    Results indicate that laminar sources tend to become uniform in cross-section with large vertical velocities and temperatures, thereby indicating a low lateral tendency to diffuse bouyancy and momentum. The turbulent sources diverge with a rapid diffusion of bouyancy and momentum depending upon the mixing length proportionality constant.

    Application of the turbulent point source results to a finite area source has been presented by postulating that the dependent variables of indraft velocity, maximum temperature and maximum vertical velocity of the finite area source can be produced by a point source of equivalent heat strength functioning at a specified distance below the finite source. Data concerning the behavior of the aforementioned variables induced by a finite area heat source do not exist. Therefore, experimental investigations are necessary to provide guidance for further analysis.

    Publication Notes

    • You may send email to to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    Scesa, S.; Sauer, F. M. 1954. Possible effects of free convection on fire behavior - laminar and turbulent line and point sources of heat. Tech. Pap. 12. Berkeley, CA: U.S. Department of Agriculture, Forest Service, California Forest and Range Experiment Station. 47 p.

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page