ADA – Aggressive Duct Aerodynamics

The ADA (Aggressive Duct Aerodynamics) project is a project coordinated by GKN Aerospace Sweden AB, carried out in collaboration with KTH. The project is implemented through two technical work packages led by GKN (WP1) and KTH (WP2) respectively. WP1 aims to understand the detailed flow in aerodynamically aggressive intermediate compressor ducts and to establish the most effective methods to predict these flows, while WP2 aims to investigate the most effective methods to extend the aerodynamic duty of such ducts by using passive and active flow control devices. ADA is intended to run in parallel to, and collaborate with, the German LuFo project RDUCT where experimental research will be done on active and passive flow control in intermediate compressor ducts by TU-Berlin and DLR in Germany. Experimental data from RDUCT will be shared with ADA.

Funded by:

Vinnova

Time period:

November 2021 - September 2023 (ADA phase 1)

November 2023 – December 2024 (ADA phase 2)

Project partner:

GKN AEROSPACE SWEDEN AB, Sweden

Background

An aggressive Intermediate Compressor Duct (ICD) turns the flow from the higher radius of the low-pressure compressor to the lower radius of the high-pressure compressor in a much shorter distance relative to ducts found in modern state-of-the-art turbofan engines. As a shorter duct has the potential for engine-weight reduction and therefore fuel savings, there is a large drive towards even shorter ICDs in the aerospace industry. However, there is a limit to how short an ICD can be made without a large loss in performance. Beyond a certain length, the flow will detach from the surfaces in the duct (i.e., the flow will not follow the curvature and direction of the walls) in what is known as flow separation. The consequence of a flow separation is a step increase in the aerodynamic losses. Furthermore, large non-uniformities and unsteadiness in the exiting flow originating from the separation might be beyond what can be handled safely by the downstream compressor.

Intermediate compressor duct with separated flow regions

Aims and objectives

The project aims at the benefits of the ICD performance by introducing flow control devices, a technology that is not currently being used in aircraft engines to push the design space of ICDs.

Detailed objectives are:

Detailed analysis of aggressive intermediate compressor duct’s flow field.
Utilization of experimental data from CleanSky2 projects to validate methods
Investigate the impact of passive and active forms of flow control devices on ICD performance.
Quantifying the improvement and best locations for flow control parameters.
Recommendation on where flow control devices should be placed in the duct to have a high beneficial impact on performance.