Tip clearance

About: Tip clearance is a research topic. Over the lifetime, 2637 publications have been published within this topic receiving 32671 citations.

Methods and apparatus for maintaining rotor assembly tip clearances

Abstract: A gas turbine engine including an active clearance control system that facilitates extending a useful life of a rotor assembly in a cost effective and reliable manner is described. The engine includes at least one rotor assembly and an engine casing that extends circumferentially around the rotor assembly, such that a tip clearance is defined between the rotor assembly and the engine casing. The clearance control system includes a plurality of panels that couple to extend circumferentially around the engine. Each clearance control system panel includes a circumferential feed duct that is formed integrally with the panel.

Gas turbine engines

Abstract: A gas turbine engine blade tip seal consists of a sealing ring which is controlled by means of two annular control members The members are arranged such that one control member has a relatively rapid thermal response rate and the other control member has a relatively slow thermal response rate, the sealing ring being controlled such that a preferred tip clearance is maintained under varying engine operating conditions

Tip-Clearance Measurement in the First Stage of the Compressor of an Aircraft Engine

Abstract: In this article, we report the design of a reflective intensity-modulated optical fiber sensor for blade tip-clearance measurement, and the experimental results for the first stage of a compressor of an aircraft engine operating in real conditions. The tests were performed in a ground test cell, where the engine completed four cycles from idling state to takeoff and back to idling state. During these tests, the rotational speed of the compressor ranged between 7000 and 15,600 rpm. The main component of the sensor is a tetrafurcated bundle of optical fibers, with which the resulting precision of the experimental measurements was 12 µm for a measurement range from 2 to 4 mm. To get this precision the effect of temperature on the optoelectronic components of the sensor was compensated by calibrating the sensor in a climate chamber. A custom-designed MATLAB program was employed to simulate the behavior of the sensor prior to its manufacture.

Numerical investigation of the unsteady behaviour of tip clearance flow and its possible link to stall inception

Abstract: Three-dimensional unsteady calculations were performed to explore the unsteady nature of tip clearance flow and its possible linking with the spike stall inception. It was found that the interaction of the broken-down leakage vortex with the tip clearance flow formed another distinctive vortex, denoted as the tip separation vortex. It formed below the rotor blade tip section and propagated diagonally inward. This vortex propagated across the rotor passage from the pressure side to the suction side with its vortex core filled with low-energy fluid. The spike emergence during stall inception included the breakdown of the tip leakage vortex and the formation and movement of the tip separation vortex.