Power assisted engine start bleed system
A system for bleeding air from a core flow path of a gas turbine engine is disclosed. In various embodiments, the system includes a bleed valve having a bleed valve inlet configured to receive a bleed air from a first access point to the core flow path and a bleed valve outlet; and an air motor having a first air motor inlet configured to receive the bleed air from the bleed valve outlet and a first air motor outlet configured to exhaust the bleed air, the air motor configured to pump the bleed air from the core flow path of the gas turbine engine.
1 . A method of starting a gas turbine engine having a core flow path compressor section, a combustor section and a core flow path turbine section configured to provide for a core flow path extending through the gas turbine engine, comprising:
igniting the combustor section after performing the following steps:
rotating the core flow path compressor section and the core flow path turbine section;
opening a first access point to the core flow path to direct a bleed air from the core flow compressor section to an air motor compressor section of an air motor;
directing a pressurized air from a pressurized air source to an air motor turbine section of the air motor; and
driving the air motor turbine section using the pressurized air to drive the air motor compressor section to pump the bleed air from the first access point.
2 . The method of claim 1 , further comprising:
receiving the pressurized air by a first air motor inlet; and
exhausting the pressurized air at a first air motor outlet, wherein the first access point to the core flow path is positioned proximate the core flow path compressor section of the gas turbine engine.
3 . The method of claim 2 , wherein the core flow path compressor section includes a high pressure section and a low pressure section, the first access point to the core flow path positioned proximate the high pressure section.
4 . The method of claim 3 , wherein the first access point to the core flow path is positioned proximate a first downstream stage of the high pressure section.
5 . The method of claim 4 , further comprising:
exhausting the bleed air at a second air motor outlet including exhausting the bleed air to a bypass flow path of the gas turbine engine.
6 . The method of claim 5 , further including:
exhausting the pressurized air at the first air motor outlet to the bypass flow path of the gas turbine engine.
7 . The method of claim 2 , wherein the pressurized air source comprises an external pneumatic source.
8 . The method of claim 7 , wherein the external pneumatic source includes at least one of an auxiliary power unit and a ground power unit.
9 . The method of claim 2 , further comprising:
delivering at a second air motor inlet the bleed air to the air motor compressor section; and
delivering at the first air motor inlet the pressurized air to the air motor turbine section.
10 . The method of claim 9 , wherein the first access point to the core flow path is positioned proximate a first downstream stage of a high pressure section of the core flow path of the compressor section.
11 . The method of claim 1 , further comprising:
driving the air motor is driven by an electric motor.