Patent Application
20100226762
(1) Field of the Invention
The present invention relates to structural members for use in cooling compact heat exchangers used in turbine engine components.
(2) Prior Art
Compact heat exchanger arrays are used in a wide variety of turbine engine components to effect cooling of the components. Many such compact heat exchangers include arrays of pedestals. To make efficient use of compact heat exchanger pedestal arrays, cavities are created with substantial distances between inlets and exits and between side walls of the array. The pedestals within these arrays may be susceptible to fracture at temperature and deflections under operation. With time, this could lead to the hot wall bulging into the flow path due to pressure loads and temperatures. Additionally, the unsupported panel might have vibrational natural frequencies that coincide with engine forcing functions during operation, which could lead to high cycle fatigue.
In accordance with the present invention, there are provided structural members for pedestals arrays which alleviate the foregoing problems.
The present invention is directed to a turbine engine component having a flow path wall and a support wall. The turbine engine component broadly comprises at least one cooling compact heat exchanger. Each compact heat exchanger has a pedestal array and at least one structural member within the pedestal array for preventing modal crossing in operation range for preventing panel bulging, and/or for connecting the flow path wall to outer diameter support structures. The term “modal crossing” refers to a coincidence of the natural frequencies of the turbine engine component with a forcing function of the engine at operational conditions. It drives oscillations of part features and may lead to premature cyclic failure.
Other details of the structural members in a pedestal array of the present invention, as well as other objects and advantages attendant thereto, are set forth in the following detailed description and the accompanying drawings wherein like reference numerals depict like elements.
Referring now to the drawings,
To effect cooling of the component 10, a plurality of compact heat exchangers is embedded within the component. The compact heat exchangers may include a leading edge compact heat exchanger 20, a main body compact heat exchanger 22, and a trailing edge compact heat exchanger 24. Each of the compact heat exchangers 20, 22, and 24 has a flow path wall 26 and a support wall 28. The flow path wall 26 is the hot wall while the support wall 28 is the cold wall. Still further, each of the compact heat exchangers has a plurality of inlets 30 for a cooling fluid and a plurality of outlets 32.
As shown in
Embedded within each of the compact heat exchangers 20, 22 and 24 are a plurality of structural members 36. Each of the structural members 36 is designed to unite a plurality of pedestals into a larger viable cluster. For example, each of the structural members may unite from 4 to 7 pedestals. Each structural member 36 is dimensioned such that a minimum flow area 38 is maintained between the structural member 36 and the surrounding pedestals 34. Each structural member 36 is preferably a cast structure made from the same material as that from which the turbine engine component is made.
The structural members 36 may be positioned within the pedestal array in each of the compact heat exchangers 20, 22, and 24 at discrete locations to prevent modal crossing in operation range and prevent panel bulging. Further, each of the structural members 36 has a height sufficient to connect the inner diameter hot wall 26 with the outer diameter wall 28 which is connected to one or more outer diameter support structures such as the OD plate 37 located outboard of the core passages 40. The attachment features 42 may be joined to the plate 37. For example, dotted line area 53 in
If desired, a plurality of structural members 36 may be positioned in an aligned configuration (see
The structural members 36, when compared to a pedestal array, provide a more robust connection between the flow path wall 26 to the support structure of the component 10 in order to prevent bulging (creep) of the flow path wall 26. The structural members 36 also prevent modal crossings in the operating range, particularly in the blade rubtrack where the blade passing is a potential forcing function.
While the turbine engine component 10 has been described as being a blade outer air seal, it could also be a blade or a vane. The structural members could be used in any cooling compact heat exchangers in any turbine engine component.
While the turbine engine component 10 has been described as having a plurality of cooling compact heat exchangers, the component can have fewer, such as one cooling compact heat exchanger, or more than three cooling compact heat exchangers.
It is apparent that there has been provided in accordance with the present invention structural members in a pedestal array which fully satisfy the objects, means, and advantages set forth hereinbefore. While the present invention has been described in the context of specific embodiments thereof, other unforeseeable alternatives, modifications, and variations may become apparent to those skilled in the art having read the foregoing description. Accordingly, it is intended to embrace those alternatives, modifications, and variations as fall within the broad scope of the appended claims.
The Government of the United States of America may have rights in the present invention as a result of Contract No. N00019-02-C-2003 awarded by the Department of the Navy.
