Question: What did the technical device made by the british aeronautical engineer during the second world war do? 
Sentence (from "Miss Shilling's orifice"): While it was officially called the R.A.E. restrictor, it was normally referred to under various names, such as Miss Tilly's diaphragm or the Tilly orifice in reference to its inventor, Beatrice "Tilly" Shilling.
Relevant evidence: No