SynTrac Presents Research in Propulsion and Aerodynamics at AIAA Aviation Forum 2025
SynTrac successfully contributed to the AIAA Aviation Forum 2025, held in Las Vegas from 21st July until 25th July, with two technical presentations highlighting cutting-edge research in propulsion integration and aerodynamic transition. The event brought together global aerospace leaders under the theme “Navigating the Future: Sustainability, Safety, and Innovation.”
On Monday, July 21st, Alexander Tidow from DLR working on sub-project A03 presented his latest results on the integration of aft-mounted boundary layer ingesting engines in the Supersonic and Subsonic Inlets session. In his talk, titled “Integration of an Inner Mixing Aft-Mounted Engine Concept in a Research Configuration with Boundary Layer Ingestion (BLI)”, Alexander demonstrated the challenging integration task that arise with a long-duct nacelle, as well as the interferences that result from this integration between the individual components (engine, fuselage, wings, empennage). These activities are important to expand the known integration space in order to enhance efficiency and sustainability in future aviation.
The integration has highlighted valuable insights: alongside the expected inflow inhomogeneity caused by BLI, the influence of the resulting supersonic field has opened up new avenues for deeper understanding. While modifications to the inlet did not yield immediate performance gains, this outcome has provided a clear direction for targeted exploration within SynTrac through a dedicated partner project.
Importantly, the investigations demonstrated that adjusting engine incidences can positively influence the supersonic flow field in the inlet—an encouraging finding with promising implications for future optimization.
The follow up questions after the presentation focused around engine architecture and integration, underlining the complexity and importance of this area. They also reinforced the value of conducting high-fidelity investigations, which are essential for achieving a comprehensive and reliable system-level assessment.
Then on Wednesday, July 23, Elrawy Soliman also from DLR and working on sub-project A03 presented in the Stability and Transition III session. His presentation, “Evaluation of Transition Models in the Slipstream of Distributed Propulsion Systems” offered insights into transition modeling challenges on a wing immersed in the slipstream of distributed propulsion system.
The study evaluates two transition transport models, namely the DLR-𝛾 model and 𝛾-𝑅𝑒_𝜃𝑡, in both steady and unsteady computations.
In the steady computations, local variations in the angle of attack modify the pressure distribution, which is the primary effect influencing the transition location on the wing. In the unsteady computations, the propellers’ effect on the pressure distribution is combined with the effect of the helical vortices impinging on the wing, changing the boundary layer characteristics. The transition criterion of the DLR-𝛾 model indicates an upstream shift of transition in sync with the blade-tip vortex impinging on the leading edge, followed by a downstream displacement as the vortex convects downstream.
Both the 𝛾-𝑅𝑒_𝜃𝑡 and the DLR-𝛾 models present a valuable opportunity for further development, particularly in enhancing their responsiveness to unsteady flow conditions. Advancing these models to more accurately capture transition under varying inflow conditions in unsteady computations could notably improve their predictive capabilities.
These contributions underscore SynTrac’s commitment to advancing the frontiers of aerodynamic and propulsion technologies — particularly those that support the transition to cleaner, more efficient aviation.
Beyond the technical contributions, the forum offered a valuable opportunity to discuss SynTrac research with international peers, exchange ideas, and establish new professional connections. It was also a pleasure to reconnect with familiar faces — including Prof Jan Delfs from DLR, a principal investigator of sub-project C05 — further strengthening the collaborative ties that support progress in aerospace research and development.
Photo: SynTrac
