Patent ID: 11927135
Assignee: PRATT & WHITNEY CANADA CORP.
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. A method for thermally regulating oil in a gas turbine engine (GTE), comprising:
passing a first air flow of ambient air at a first temperature within an air duct during a first mode of operation of the GTE;
passing a second air flow of ambient air at a second temperature within the air duct during a second mode of operation of the GTE, wherein the first temperature is greater than the second temperature; and
pumping a flow of oil through an oil tank, the flow of oil having a first portion and a remaining portion, the oil having a viscosity that varies as a function of temperature, the oil tank having an interior cavity at least partially defined by at least one structural wall, wherein the at least one structural wall includes an interior side surface contiguous with the interior cavity and an exterior side surface opposite the interior side surface, a plurality of first heat transfer protrusions extending outwardly from the exterior side surface and into the air duct, and a plurality of second heat transfer protrusions extending outwardly from the interior side surface and into the interior cavity, wherein the plurality of second heat transfer protrusions are spaced apart from one another and thereby define flow passages amongst the plurality of second heat transfer protrusions;
wherein the interior cavity of the oil tank and the plurality of second heat transfer protrusions are configured so that the plurality of second heat transfer protrusions are immersed in the flow of oil during operation of the GTE; and
wherein the interior cavity of the oil tank, the plurality of second heat transfer protrusions, and the oil are configured such that in the second mode of operation the first portion of the flow of oil is disposed within the flow passages amongst the plurality of second heat transfer protrusions and the first portion of the flow of oil thermally insulates the remaining portion of the oil and thereby mitigates heat transfer between the remaining portion of the flow of oil and the plurality of first heat transfer protrusions; and
wherein in the second mode of operation of the GTE the first portion of the flow of oil disposed within the flow passages is substantially stationary.