Session: Student Poster Competition

Submission Number: 187127

Methodology for Replicating Rotating Detonation Combustor Outflow Conditions in a Linear Subsonic Turbine Cascade 

Rotating Detonation Combustors (RDC) represent a significant technological advancement in the field of gas turbine efficiency, offering the potential for pressure gain combustion. However, the integration of RDCs with downstream turbomachinery poses significant aerothermal challenges. The flow at the combustor exit is characterized by extreme unsteadiness, including high-frequency pressure fluctuations, supersonic distinct peaks, and large variations in flow angle (30 deg). Testing turbine vanes under these realistic conditions usually requires complex, expensive, and short-duration hot-fire rigs.

This PhD project, part of the H2POWRD MSCA Doctoral Network, addresses this challenge by establishing a robust methodology to reproduce the representative aerodynamic features of an RDC outflow within a continuous, cold-flow linear wind tunnel (VKI C3 facility).

The primary focus of the research is defining the scaling laws necessary to translate the supersonic, high-temperature RDC environment into subsonic, cold laboratory conditions. To define the target flow field, unsteady CFD simulations were performed on a baseline turbine geometry. These numerical studies are utilized to identify the generic flow trends and the boundary condition ranges, specifically the inlet angle and pressure fluctuation patterns, that must be replicated, independent of the specific vane design. By matching key non-dimensional parameters (e.g., reduced frequency, unsteady pressure coefficient) derived from these trends, we aim to isolate the aerodynamic response of the turbine vane to detonative flows.

To achieve this, the work investigates novel experimental concepts for active flow modulation. Specifically, the study explores the feasibility of variable-geometry pressurized wake generators and other actuation systems designed to synthetically reconstruct the shear and extreme incidence fluctuations typical of RDC exhausts. The poster presents the theoretical scaling framework, the numerical identification of the target flow features, and the conceptual design of the proposed test rig. This research aims to provide a cost-effective platform to optimize turbine vane geometries for next-generation hydrogen propulsion systems.

Presenting Author: Francesco Porta von Karman Institute for Fluid Dynamics

Presenting Author Biography: Francesco Porta is a PhD candidate under the department of Turbomachinery and Propulsion at the Von Karman Institute for Fluid Dynamics. His research explores the impact of rotating detonation combustion flow conditions on subsonic turbine cascades, using a combination of experimental and numerical investigations. Previously, he focused on developing data-driven inverse design tools for turbomachinery blades, combining CFD and machine learning to improve aerodynamic design and turbine optimization. Francesco’s work showcases his passion for innovation, strong leadership, and dedication to rigorous experimentation and technological progress, driving his pursuit to excel as a competitive engineer.

Authors:

Francesco Porta von Karman Institute for Fluid Dynamics
Sergio Lavagnoli von Karman Institute for Fluid Dynamics