EXPERIMENTAL INVESTIGATION OF SIMULATED ICE ACCRETION ON TURBOPROP AIRCRAFT

摘要

An experimental investigation wasrnconducted to study the aerodynamic effect ofrnsimulated ice accretion on a wing andrnhorizontal tailplane of an aircraft by means ofrnwind tunnel testing. The aircraft was of a twoenginernturboprop commuter type. Ice accretionrnwas simulated by strips of different shapesrnpositioned either ahead of the right aileron orrnahead of the elevator. The strips of two crossrnsections were examined, of a V shape sectionrnsimulating a conventional leading-edge icernaccretion and of a quadrantal section withrnfront edge perpendicular to the upper surfacernof the airfoil simulating an ice accretionrncaused by supercooled large droplets. Itsrninfluence on the basic aerodynamicrncharacteristics of the aircraft was evaluated, i.rne. the lift, drag, side force and moments.rnThe V shape ice accretion strip wasrnpositioned at the leading edge of the wing orrnthe stabiliser, the quadrantal strip from 5 % torn45 % of chord. The deflections of aileron werernup to 30 degrees and the angle of attack wasrnchanged from 0 up to the angle of maximumrnpositive lift coefficient. The deflections ofrnelevator were up to 10 degrees down and 27rndegrees up and the angle of attack wasrnchanged from 0 up to the angle of maximumrnpositive lift coefficient. Wind tunnel tests werernperformed in the VZLú 3 m diameter low -rnspeed wind tunnel.rnSimulation strips correspond with aviationrnauthorities requirements andrnrecommendations, so the data obtained fromrnthe wind tunnel measurements could indicaternthe development of aerodynamicrncharacteristics which can be caused by thernphenomenon of ice accretion under naturalrnconditions. It is clear that ice accretion can leadrnto large losses in lift, increases in drag andrnchanges in the moments. Especially behaviourrnof the rolling and pitching moments is of greatrninterest as they are connected closely with therncontrol of aircraft in complex conditions.