Patent ID: 7454894
Filing Date: 2008-11-25
Classification: F01D,F02C,F02K,Y02T

Abstract:
1. A gas turbine engine comprising: a turbo fan driven by a turbine section, said turbo fan being driven at a variable speed dependent on operational conditions of the gas turbine engine, an air passage receiving airflow from said turbo fan, and air in said air passage passing over a heat exchanger, said heat exchanger receiving oil, said oil being communicated through said heat exchanger from at least one component associated with the gas turbine engine; a supplemental airflow system for selectively supplying supplemental air over said heat exchanger at times when said turbo fan is operating at a relatively lower speed such that the airflow in said air passage is relatively low, the supplemental air coming from an ambient air source; and a nacelle surrounds said turbo fan, with said air passage being radially inward of said nacelle, and said supplemental air being taken from a location radially outward of said nacelle.