Computational investigation on infrared radiation characteristic for two-dimensional vectoring nozzles with fluidic injection
Relative to the thrust vectoring nozzle by mechanical means, fluidic injection vectoring nozzle outshines on the strength of uncomplicated structure, light weight and low cost. Research on infrared characteristic of fluidic injection vectoring nozzles is highly vital for nozzle technology development and military application. Numerical simulation for infrared characteristic of the two-dimensional fluidic injection vectoring nozzles was conducted employing self-developed program software. Based on the computational results, it can be concluded that two-dimensional throat skewing nozzle possesses optimal infrared characteristic suppression effect among the nozzle schemes.
ADVANCES IN THRUST VECTORING AND THE APPLICATION OF FLOW-CONTROL TECHNOLOGY
A review of thrust-vectoring initiatives shows thrust-vectoring technology to be a proven concept that enhances the projection of aerospace power with many advantages, including improved aircraft maneuverability, performance, survivability, and stealth. Mechanical thrust-vectoring designs, however, have proven to be heavy, complex, expensive, and counter-productive to stealth. Fluidics offer reduced weight, higher reliability, and stealth compatibility. Fluidic thrust- vectoring systems have been successfully tested; although, flight testing has yet to be completed. A thrust-vectoring upgrade programme would benefit the CF-18 aircraft in retaining its viability to project Canadian aerospace power until the end of its service life.
J85 Surge Transient Simulation
A one-dimensional model is presented for simulating surge disturbance propagations throughout an entire turbojet engine. The predicted results using this model are presented for the surge transient flow phenomena and the unsteady compressor operating-point excursion during surge in a J85 turbojet engine. The unknown stalled compressor stage characteristics are represented by parameters whose range was determined through a parametric study. The predicted stalled characteristics showed faster responses and larger pressure-ratio deterioration compared to low-speed compressors. Surge hammer overpressures were found to have a triangular shape in the time-space (engine axis) domain. The mass flow through the compressor was found to approach zero in 10-20 ms, thus affecting the peak hammer overpressures at the intake duct and the temperature rise in the compressor. Different stall methods were found to result in different compressor operating-point excursions.