A gas turbine engine includes a main engine compressor section. A booster compressor changing a pressure of airflow received from the main engine compressor section to a pressure desired for a pneumatic system. The booster compressor operates at airflow conditions greater than a demand by the pneumatic system. A speed change system driving the booster compressor at speeds corresponding to a demand of the pneumatic system. A bleed air system for a gas turbine engine and a method of controlling engine bleed airflow are also disclosed.

A gas turbine engine includes a main engine compressor section. A booster compressor changing a pressure of airflow received from the main engine compressor section to a pressure desired for a pneumatic system. The booster compressor operates at airflow conditions greater than a demand by the pneumatic system. A speed change system driving the booster compressor at speeds corresponding to a demand of the pneumatic system. A bleed air system for a gas turbine engine and a method of controlling engine bleed airflow are also disclosed.

A gas turbine engine includes a main engine compressor section. A booster compressor changes a pressure of airflow received from the main engine compressor section to a pressure desired for a pneumatic system. The booster compressor is configured to operate at airflow conditions greater than a demand of the pneumatic system. An exhaust valve controls airflow between an exhaust outlet and an outlet passage to the pneumatic system. The exhaust valve is operable to exhaust airflow from the booster compressor in excess of the demand of the pneumatic system. A bleed air system for a gas turbine engine and a method of controlling engine bleed airflow are also disclosed.

A gas turbine engine includes a main engine compressor section. A booster compressor changes a pressure of airflow received from the main engine compressor section to a pressure desired for a pneumatic system. The booster compressor is configured to operate at airflow conditions greater than a demand of the pneumatic system. An exhaust valve controls airflow between an exhaust outlet and an outlet passage to the pneumatic system. The exhaust valve is operable to exhaust airflow from the booster compressor in excess of the demand of the pneumatic system. A bleed air system for a gas turbine engine and a method of controlling engine bleed airflow are also disclosed.

A variable speed pumping system, for an aircraft, comprising: a first electrical machine, the first electrical machine comprising an electrical machine rotor shaft mechanically connected to an engine of the aircraft and electrical machine stator coils; an electric pump motor-generator, the electric pump motor-generator comprising an electric pump rotor shaft mechanically connected to the electrical machine rotor shaft via a one way drive arrangement and electric pump stator coils; wherein the electric pump rotor shaft is mechanically connected to a fluid pumping system.

A variable speed pumping system, for an aircraft, comprising: a first electrical machine, the first electrical machine comprising an electrical machine rotor shaft mechanically connected to an engine of the aircraft and electrical machine stator coils; an electric pump motor-generator, the electric pump motor-generator comprising an electric pump rotor shaft mechanically connected to the electrical machine rotor shaft via a one way drive arrangement and electric pump stator coils; wherein the electric pump rotor shaft is mechanically connected to a fluid pumping system.

Described herein are embodiments of systems and methods for the removal of a direct drive unit (DDU) housed in an enclosure, such as a direct drive turbine (DDT) connected to a gearbox for driving a driveshaft connected to a pump for use in hydraulic fracturing operations.

According to one aspect, a clutch mechanism includes a control member. The control member is adapted to receive motive power and includes a first dry clutch member and a first viscous clutch member. The clutch mechanism further includes an output member that includes a second dry clutch member and a second viscous clutch member. The first and second dry clutch members form a dry clutch and the first and second viscous clutch members form a viscous clutch. The clutch mechanism further includes an actuation arm coupled to at least one of the control and output members. The actuation arm is selectively controllable to effect relative movement of the control and output members such that one of the dry and viscous clutches is selectively engaged.

Embodiments of a power generation system and methods to be used in conjunction with a high-powered turbine engine are disclosed. The power generation system includes a turbine engine having an exhaust diffuser section installed on the exhaust duct of the turbine engine and a turbine engine exhaust stack assembly connected to the turbine engine exhaust diffuser section. An embodiment further includes thermo-electric generator (TEGs) sub-assemblies connected to the turbine engine exhaust stack assembly. In other embodiments electrical storage devices such as batteries are used.

Embodiments of a power generation system and methods to be used in conjunction with a high-powered turbine engine are disclosed. The power generation system includes a turbine engine having an exhaust diffuser section installed on the exhaust duct of the turbine engine and a turbine engine exhaust stack assembly connected to the turbine engine exhaust diffuser section. An embodiment further includes thermo-electric generator (TEGs) sub-assemblies connected to the turbine engine exhaust stack assembly. In other embodiments electrical storage devices such as batteries are used.