Gas turbine engines often include so-called "start injectors" that are used when initiating operation of the turbine. Start injectors operate on the principal of pressure atomization and as a consequence, in relatively small turbine engines in airborne environments whereat fuel flows at high altitudes during starting may be quite low, high pressures are required to achieve the pressure atomization required of a start injector. Air blast atomization is not a viable alternative during starts when the turbine is rotating at a minor percent of its rated speed. At the same time, at such low speeds, it is difficult with available fuel pumps to generate the necessary fuel pressure.
To meet these difficulties, conventional start injectors have extremely small orifices to provide the desired atomization making them precision formed parts. They are thus costly to manufacture and at the same time, because of the very small orifices employed, they are prone to plugging.
In the above-identified application of Shekleton, there is disclosed a unique fuel injector construction for a turbine engine that is of low cost construction and which may advantageously be employed both as a start injector and as a main fuel injector and which does not require high fuel pressures to achieve good atomization. The present invention is directed to improving upon the invention disclosed in the previously identified Shekleton application.