LASER DIAGNOSTIC METHODS FOR VELOCITY MEASUREMENTS IN COMBUSTIVE FLOWS

Increased vehicle fuel economy through improvements in engine operation depends on improved fundamental understanding of the combustion process by modern diagnostic techniques such as laser anemometry. Here we discuss (a) new techniques of time resolved, single point velocity measurements and larger scale mapping by seed particle track imaging, and (b) applications of these methods to cycle-resolved engine flow studies and to other model flows relevant to IC engines. The point measurements rely on the recording and storage of the complete time evolution of the light scattering from seed particles crossing a suitable fringe system, at sufficiently high seeding rates to obtain a continuous velocity measurement. The larger scale flow mapping records the images of seed tracks by a conditional sampling technique on the output of an intensified vidicon detector. A system for acquisition of velocity field data in operating engines will be described and data for studies of the nature of cyclic velocity fluctuations in motored and firing engines will be discussed, as well as measurements of unstable flow in conventional burner assemblies.

Media Info

  • Features: Figures; References;
  • Pagination: p. 127-142

Subject/Index Terms

Filing Info

  • Accession Number: 00393094
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: Proceeding, HS-037 234, HS-037 235
  • Files: HSL, USDOT
  • Created Date: Mar 29 1985 12:00AM