Masakatsu Matsuki

Measurement of blade tip clearance using an ultrasonic sensor

This paper describes a development and evaluation of a blade tip clearance measurement system using an ultrasonic sensor. Special features of this system are; (i) it is adequate for metal and non-metal blade; (ii) it permits measurement without contact; (iii) it can work in dirty environment; and (iv) it is easy to install. Experimental results using a rotating blade test rig are described. Blade tip speed is restricted to Mach 0.18 due to the limitation of the test rig. It is concluded that the ultrasonic method is a promising candidate for an on-line clearance control of gas turbine engines.

Oil Squeeze Film Dampers for Reducing Vibration of Aircraft Gas Turbine Engines

Theoretical analysis and experiments were carried out on cylindrical oil squeeze film dampers. The finite element method (FEM) was applied for calculating pressure distribution in the dampers with end seals and oil grooves. Measurements of the viscous damping coefficient of several dampers were conducted and compared with theoretical values. The effects of the dampers on the vibrational characteristics of engines were reviewed through theoretical analysis and experiments on an engine model. Then, the effects of squeeze film dampers on an actual engine were evaluated for design information.© 1979 ASME

Recent status on development of the turbofan engine in Japan

Efforts to design and develop new jet engines have been made in Japan since 1953. One family of propulsion engine (J3) succeeded in getting into production to be installed on two models of Japanese developed aircraft (T1B and P2J). Another family of lift engine (JR) has been successfully used for overall VTOL system studies. Based on these experiences, studies on a new fan engine for main propulsion are being carried out. This new engine (FJR-710) is a high bypass front engine developed for low noise generation and low smoke emission. The interim goal for the engine is an exhaust smoke density below AIA 25. A combustor of the air-swirl atomizer type has been adopted which can successfully reduce smoke.

Status Report of the Turbofan Engine Development Program in Japan

A National Research and Development Program of high bypass ratio turbofan engines has been in process in Japan since 1971. Target performance characteristics of the first-phase 5-ton thrust class engines have been attained, and development of the second-phase engines has been started in 1976. This paper reviews the status of the program, discusses some engineering progress attained, and presents an outline of the second-phase program and engines.Copyright

Lift Jet Engine, JR100

As part of the program for developing VTOL craft, the National Aerospace Laboratory (NAL) of the Japanese Government installed two JR100 lift jet engines on their Flying Test Bed, following upon the successful outcome of tests on the Height Control Tower with other JR100 engines. These JR100 engines were developed in a joint effort between NAL and IHI. Five engines in three successively modified version have been produced, and the aggregate number of runs has already reached 1700, recording accumulated operating time of more than 200 hrs. The engine which has a 6-stage compressor, an annular combuster and a single-stage turbine, produces 3350 lb thrust and weighs 340 lb.Copyright