Spreadsheet calculations of jets injected normal to a crossflow in a rectangular duct from opposed rows of slots slanted at 45°

Abstract

The purpose of this study was to show expected results for cases of opposed rows of jets entering the mainstream from 45° slanted slots and round holes. The results in this paper were obtained using the spreadsheet version of the NASA JIC empirical model posted with NASA/TM—2011-215980. This version incorporates two significant changes that only affect slanted slots: 1) the translation function was corrected so distributions for round holes (as L/W=1 slanted slots) do not translate and 2) the capability was added to allow 45° slots to slant in either direction so “crossed” slot configurations can be calculated.The primary conclusion in this paper is that the best mixing configuration for opposed rows of slanted slots, at any downstream distance, is a parallel staggered configuration. Although distributions from “crossed” slanted slots are similar to those from parallel configurations at particular locations, results for crossed slots are highly dependent on downstream distance and are no better than parallel slots at locations where they are similar and are worse than parallel ones at other distances.