Thin flat internal strain gauge balances for testing slab delta wing models at hypersonic speeds

Details of a 2.5 mm thick, 3-component balance and a 4 mm thick, 6-component balance, which can be housed inside thin slab delta wing models are given. The 3-component balance has been used to generate data on aerodynamic characteristics of slab delta wing models in the pitch plane and to demonstrate the considerable amount of interference introduced by lee-side housings used in conjunction with regular balances (which cannot be housed inside the slab delta wing model), not only at small incidences but also at incidences where the housings are supposed to be completely in the aerodynamic shadow of the wing. Some of these aerodynamic data which have been obtained at M=8.0, in the 200 mm hypersonic pressure-vacuum blow-down wind tunnel of Indian Institute of Science, Bangalore, are presented