Title: The Design, Analysis and Testing of an Advanced Cascade Design

Authors: Henry A. Schaefer and Mark A. Wadsworth

DOI: 10.33599/nasampe/c.19.0777

Abstract: The majority of underwing turbofan engines utilize Translating Sleeve-Cascade thrust reversers to augment the aircraft braking system. When the thrust reverser is deployed the translating sleeve slides aft which exposes the cascade baskets to bypass air. The cascades themselves use vanes to redirect the airflow forward and away from the aircraft. This provides the reverse thrust and efflux control required for efficient aircraft landing control.

Originally, cascades were designed to be metallic castings, but for the last 30 years, cascades have been fabricated from carbon/epoxy in a hand-layup process. This provided a more weight efficient design but still had significant challenges from a manufacturing perspective. The hand-layup aspect is very time consuming and limits the configuration for both vanes and structural members. By limiting the cross-sectional configuration of the vanes, the cascades are not optimized for airflow efficiency nor are they configured to minimize noise generation during the thrust reverser deployment.

A novel cascade design has been developed which addresses some of the limitations of currently available cascade configurations. This new design utilizes advances in manufacturing technologies as well as material selection. Structural frames are fabricated using the drape forming technique while the end caps are created using compression molding. Carbon/Epoxy is used for each of these components. The vanes are produced from the thermoplastic PPS material utilizing the injection molding process. This allows the manufacturing of the high quantity of vanes required as well as the complex geometry associated with an optimized cascade basket. The frames, end caps and vanes are then bonded together to produce the cascade basket assembly.

To evaluate the innovative design, several cascade assemblies were manufactured and structurally evaluated. The results demonstrated that the new design can be easily manufactured and the structural capabilities met all required design objectives. A thorough review of vibration, static, airflow, and fatigue testing will be discussed.

References: 1. Nikkiso Website, Aerospace Products and Services 2. Michael L. Vermilye, The Boeing Company, Seattle, Wash. US Patent for “Hybrid Thrust Reverser Cascade Basket and Method”, Patent No. 4,852,805, filed Dec. 30, 1983 3. Clint A. Luttgeharm, Marty J. Todd, John M. Welch, The Boeing Company, Seattle Wash, US patent for “Cascade Assembly for Use in a Thrust-Reversing Mechanism, Patent No. 5,507,143, filed Apr. 1, 1994 4. Michael J. Holme, Jeffrey C. Bishop, Rolls-Royce plc, London(GB), US Patent for “Flow Directing Element and a Method of Manufacturing a Flow Directing Element”, Patent No. 6,725,541, filed Mar. 26, 2003 5. Thomas P. Forman, et. al, Dow-United Technologies Composite Products, Inc. Wallingford, Conn. US Patent for “Process for Making Braided Composite Part”, Patent No. 5,624,618, filed Jun. 7, 1995 6. Luis Gustavo Trapp and Guilherme L Oliveira, “Aircraft Thrust Reverser Cascade Configuration Evaluation Through CFD”, 41st Aerospace Sciences Meeting and Exhibit, AIAA 2003-723 7. Orlando A. Gutierrez, James R Stone, and Robert Friedman, “Results from Cascade Thrust Reverser Noise and Suppression Experiments”, J. Aircraft, Vol. 12, No 5, May 1975: 479-486

Conference: CAMX 2019

Publication Date: 2019/09/23

SKU: TP19-0777

Pages: 15

Price: $30.00