Browse Prior Art Database

CMC COMBUSTOR LINER AND SEALING ARRANGEMENT

IP.com Disclosure Number: IPCOM000247851D
Publication Date: 2016-Oct-06

Publishing Venue

The IP.com Prior Art Database

Abstract

The invention relates to a gas turbine aircraft engine combustor. Specifically, an arrangement of ceramic matrix composite (CMC) tiles and seals for a combustor liner is disclosed.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 23% of the total text.

Page 01 of 13

CMC COMBUSTOR LINER AND SEALING ARRANGEMENT

TECHNICAL FIELD

    The invention relates to a gas turbine aircraft engine combustor. Specifically, an arrangement of ceramic matrix composite (CMC) tiles and seals for a combustor liner is disclosed.

BACKGROUND

    Improvements in manufacturing technology and materials are the keys to increased performance and reduced costs for many articles. As an example, continuing and often interrelated improvements in processes and materials have resulted in major increases in the performance of aircraft gas turbine engines. One of the most demanding applications for materials can be found in the components used in aircraft jet engines. The engine can be made more efficient resulting in lower specific fuel consumption while emitting lower emissions by operating at higher temperatures. Among the current critical limitations on the achievable operating temperatures of the engine are the materials used in the hottest regions of the engine, which include the combustor portion of the engine and the portions of the engine aft of the combustor portion including the turbine portion of the engine. For example, temperatures in the combustor portion of the engine can approach or exceed 3500°F.

    One of the portions of the engine in which a higher operating temperature is desired so that overall operating temperature of the engine can be achieved is the combustor chamber. Here, fuel is mixed with air and ignited, and the products of combustion are utilized to power the


Page 02 of 13

engine. The combustor chambers include a number of critical components, including but not limited to the swirler/dome assembly, seals and liners. In the past, these components have been made of metals having similar thermal expansion behavior, and temperature improvements have been accomplished by utilization of coatings, back side convection cooling, bore cooling from multi-hole film holes, film cooling inside the liner, and combinations thereof. However, as the operating temperatures have continued to increase, it has been desirable to substitute materials with higher temperature capabilities for the metals.

    Ceramic matrix composite (CMC) materials have been used in aircraft combustor liners as they have great strength at extremely high temperatures. As noted previously, the combustors operate at different temperatures throughout the operating envelope of the engine causing differing amounts of thermal expansion in different parts of the liner which leads to stress in the materials leading to failure and short life cycles. CMC combustor liner designs have been proposed having different shapes and cooling methods to help combat this problem. For example, some designs use multiple CMC segments axially spaced within the combustor. In such a configuration, gaps can form between segments either intentionally or unintentionally which let cooling air into the combustion chamber and cause local hot spots. This can lead to even more local temper...