Steady Reynolds-Averaged Navier-Stokes (RANS) simulations utilizing the k-ω SST turbulence model are conducted to investigate the aerodynamic performance of a wing-integrated ram-air duct housing a heat exchanger for propeller-driven aircraft, including its impact on wing-body junction flow. The research is conducted in two stages: first, a 2D aerodynamic analysis employing a Design of Experiment (DoE) methodology to assess the sensitivity of key geometrical parameters–including stagger angle, leading-edge droop, duct gap, and heat exchanger characteristics–on lift, drag, and duct mass flow rate; and second, a 3D investigation of the junction flow behavior in the nacelle/ducted-wing configuration. The heat exchanger pressure drop is modeled as a porous media zone using the Darcy-Forchheimer quadratic drag law. Heat transfer is incorporated through a variable energy source term applied via a userdefined function (UDF) based on the ε-NTU correlation. Findings from the 2D aerodynamic analysis indicate that heat exchanger characteristics, particularly porosity and thickness, have a more pronounced impact on aerodynamic performance than external duct geometry. However, intake stagger angle and leading-edge droop play critical roles in mitigating flow separation and optimizing the wing pressure distribution. In addition, the redistribution of pressure due to flow restriction alters the stagnation point location, inlet-velocity ratio, and static pressure distributions, all of which influence the aerodynamic loading of the ducted wing. The optimal ducted airfoil configuration, featuring a lower-surface outlet aft of the maximum thickness and a thin heat exchanger, minimizes aerodynamic penalties while maximizing duct mass flow rate. However, thermal feasibility assessments reveal that meeting the cooling demands of fuelcell systems necessitates a thicker heat exchanger to accommodate sufficient heat transfer area within the constrained wing volume. This increase in thickness impairs aerodynamic performance through increased pressure drop and resultant drag. Although higher porosity mitigates flow resistance, the required thickness offsets this advantage, reinforcing the inherent trade-off between aero-thermal performance. In 3D, the presence of the heat exchanger inside the duct fundamentally alters the local aerodynamics by modifying boundary layer interactions at the wing-body junction. The flow resistance imposed by the heat exchanger directly affects the strength and topology of secondary flow structures, particularly the horseshoe vortex (HSV), which governs junction flow behavior and whose strength scales with the Reynolds number based on the momentum thickness of the incoming boundary layer. At low porosity levels, the stronger HSV , with an increased vertical extent above the wing, entrains high-momentum freestream flow into the chordwise and spanwise boundary layers, mitigating corner flow separation. Conversely, at high porosity levels, lower flow resistance alters HSV topology, reducing its vertical extent and allowing part of the vortex to enter the duct, inducing a secondary vortex at the lower lip. This weakens the HSV’s ability to stabilize the boundary layer, leading to earlier separation, increased pressure losses, and higher drag. A moderate porosity level provides an optimal balance between HSV strength, vertical positioning, and junction flow stability, reducing corner flow separation and associated pressure losses. Collectively, these findings yield critical insights into integrating ram-air cooling ducts within the wings of propeller-driven aircraft, offering a compelling approach to achieving efficient thermal management systems with minimal aerodynamic penalty. This investigation provides unprecedented detail in visualizing and understanding the intricate coupling between ducted wing aerodynamics and heat exchanger-induced flow interactions, while emphasizing the need for further research to validate and expand upon these findings

Liquid hydrogen has been identified as a low-emission alternative to hydrocarbon fuel sources for aircraft. Although there has been a notable increase in the number of studies and technology readiness of liquid hydrogen technologies in the recent decade, there is still more research and development necessary to realize commercially viable hydrogen-fueled aviation. Achieving zero boil-off by using active cooling has been identified as a potential method of decreasing the mass and volume of a future liquid hydrogen fueled aircraft. However the lack of literature or data on the thermal performance and specific power of cryocoolers for this application makes it difficult to assess its feasibility. Therefore, a study was performed to develop a reverse turbo-Brayton cryocooler simulation tool, focused on the three heat exchangers of this cooler type. This paper presents the methodology for the development of this tool alongside a case study on a liquid hydrogen fuel tank for TU Delft's flying-V concept. From the case study it has been concluded that the considered RTBC design offers a reduction in the liquid hydrogen mass, however not significant enough to offset the cryocooler's own weight. An improved performance and specific power of the individual components would be required to achieve a net weight reduction.

The final report focused on the detailed design of the final chosen concept, which is a BWB aircraft with a distributed propulsion system powered by liquid hydrogen. Before doing the actual technical design part, a market analysis is made to investigate the future demand for this type of aircraft. To do so, the SWOT analysis, market characteristics, and competitor analysis are made. After that, an estimation of the market dynamics & trends, as well as the expected demand for the aircraft is made. In financial analysis, the financial forecast and strategies for the whole aircraft program are discussed, from which the unit cost, operational cost, return on investment and cost-breakdown structure can be found. The report concludes that the Lightning2 program is a promising step towards more sustainable aviation. It emphasizes the need for further development and adaptation to technological advancements to maintain a competitive position in the market​