Inviscid Theory of Wall Interference in Slotted Test Sections,
Abstract
The classical theory of longitudinally slotted walls, which substitues an approximate homogeneous wall boundary condition for the true mixed conditions, is extended in several respects. Based on recent experimental findings at the FFA, an inviscid flow model is adopted in which the outgoing slot flow penetrates into the plenum chamber as thin jet, while the re-entering flow, admitting quiescent air from the plenum chamber into the test section, induces a longitudinal separation bubble at plenum pressure along the slot and adjacent parts of the test section wall. The three-dimensional analysis, based on the assumption that the slots are narrow, retains quadratic cross-flow terms in the pressure equation and allows the slots to be few in number and have non-uniform distribution and geometry. A family of homogeneous boundary conditions is obtained, each of successively higher accuracy. Application to the design of interference-free transonic test sections is discussed. Unsteady effects are also considered. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1976
- Accession Number
- ADA034094
Entities
People
- Sune B. Berndt
Organizations
- National Aeronautical Research Institute