REVIEW OF ACTIVE CLEARANCE CONTROL SYSTEMS USED IN AIRCRAFT ENGINE BUILDING. DIRECTIONS AND DEVELOPMENT PROSPECTS

World manufactures are focused on consumer features of products in the design of TPD.Special attention is paid to im-proving the efficiency of engines. Tip clearance significantly influences on the efficiency of turbine and the specific fuel con-sumption. Minor tip clearance change in turbine can lead to a significant increase in fuel consumption. That is what the active clearance control system (ACC) exists. The main purpose of ACC is to regulate the thermal inertia of stator (in existing serial systems) and to maintain the desired tip clearance. The aim of this review article is to explore the variety of different ACC used in the serial production of gas turbine en-gines. The classification of ACC are distinguished by design (for HPT and LPT) and by control logic based on the considered data on turbines of serial engines from leading world manufactures (such as Rolls Royce, Pratt & Whiney, CFM, General Elec-tric, Aviadvigatel). As a key factor for the classification of ACC by design, the method of supplying cooling air and the configura-tion of the casing blowing cavity were selected, the classification of ACC by control logic includes two options (two-position and program systems). In addition to the classification the ways of improving the existing serial systems were identified, which con-sist in increasing the speed of regulation. The promising ACC that are fundamentally different from the existing serials one by design and control logic were presented. Mechanical systems are used for ground engines and thermal systems are used for aircraft engines, whose control logic is based on mathematical modeling.