An Analytic Investigation of Accuracy Requirements for Onboard Instrumentation and Film Data for Dynamically Scaled Wind Tunnel Drop Models

Book excerpt: An analytic study was conducted to evaluate anticipated ranges and required accuracies for onboard linear acceleration and angular rate (or acceleration) measurement equipment to be mounted within dynamically scaled wind tunnel drop models. Generic simulations of the separation motion of a tumbling fuel tank both at full scale and at 1/15th wind tunnel model scale were generated using an analytic trajectory simulation program coupled with a prescribed aerodynamic database. The simulations provide a basis for sizing the required instrumentation for proof of concept demonstrations of telemetry techniques in the wind tunnel. The simulations were also used as test cases to demonstrate extraction of aerodynamic information from drop data positions and orientations as read from film records via an inverse solution of the store equations of motion. The studies also aid identification and evaluation of inaccuracies associated with the basic dynamic scaling laws and standard film based data reduction techniques.