Hybrid ram air turbine with inlet guide vanes

Abstract

A hybrid ram air turbine includes a generally conical-shaped shaft which mounts a number of vanes wrapped in a substantially helical orientation along the shaft with a portion of each vane being formed in the general shape of a reaction turbine blade and another portion in the general shape of an impulse turbine blade. A number of fixed inlet guide vanes having a convergent wedge shape direct a flow of air onto the blades of the turbine which is mounted within the interior of a pod.

Description

FIELD OF THE INVENTION[0001]This invention relates to submerged ram air turbines, and, more particularly, to a hybrid submerged ram air turbine having a generally conical-shaped shaft that mounts helically wrapped blades formed with a first portion shaped like a reaction turbine blade and a second portion shaped like an impulse turbine blade wherein an air flow is directed onto the blades through a number of fixed, inlet guide vanes.BACKGROUND OF THE INVENTION[0002]Ram air turbines are commonly used in military and commercial aircraft to provide a source of hydraulic or electrical power in the event of an emergency. Modern aircraft generate power through the main engines or via an auxiliary power unit such as a fuel-burning turbine typically located in the tail of the aircraft In most applications for commercial aircraft, ram air turbines are retracted into the fuselage or wing(s) under normal operating conditions, but are deployed in the event of an emergency loss of power. They ty...

AI Technical Summary

Benefits of technology

[0007]A number of features of this invention contribute to increasing the power output of the turbine herein, which, in turn, results in the generation of more electrical power than prior art designs. The orientation and shape of the inlet guide vanes not only directs flow onto the blades of the turbine, but increases pressure of the air flow at the inlet end of the pod immediately upstream from the turbine blades. The increased, axially extending surface area of the blades, as well as the blade shape, enhances the pressure differential across the blade surfaces to create increased torque. More torque translates into more power. Further, the generally conical shape of the shaft of the turbine reduces the cross sectional area between the shaft and pod wall as the air flow moves from the inlet toward the outlet of the pod, thus tending to maintain more constant pressure along the axial length of the blades which enhances the torque produced.

Problems solved by technology

Existing externally mounted and submerged ram air turbines do not provide sufficient power output, and there is a need for an improved turbine design.

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