• SMIT SHINDE
• ABHISHEK KANAJE
• ADITYA SHANKARNARAYANAN
• AASMI GUPTA
• TANVEE SHAH

In high-performance propulsion systems, bypass cooling ducts play a critical role in mitigating thermal loads and maintaining structural integrity near engine combustion zones. This paper presents a computational fluid dynamics (CFD) investigation of a curved bypass secondary flow duct designed to redirect high-speed airflow (Mach 0.5) around engine hardware. The goal is to evaluate the aerodynamic performance and thermal characteristics of the duct geometry under realistic bypass flow conditions. The CAD-based fluid domain was meshed using a tetrahedron-dominant grid strategy with uniform 20 mm element sizing. ANSYS Fluent was employed to perform steady-state, compressible flow simulations using the standard k-ε turbulence model. Boundary conditions included a velocity inlet at 300 m/s with a static temperature of 823 K, and a pressure outlet at 1 Pa. The working fluid, modeled as an ideal compressible gas, reflects typical compressor bypass bleed conditions. Simulation results indicate effective flow attachment through the curved passage, with outlet velocities preserving the Mach 0.6 profile and smooth streamline behavior across the bend. A moderate temperature rise (823 K to ~843.6 K) was observed downstream due to compressibility effects, with no evidence of shock, separation, or backflow. Path line visualizations and temperature contours confirm the duct’s suitability for stable secondary flow routing. The study also supports design recommendations for mesh refinement, wall-layer inflation, and extended iteration for final convergence. These findings validate the use of the duct as a viable cooling mechanism for engine or nacelle thermal protection and demonstrate the effectiveness of using the standard k-ε model in predicting turbulent behavior in high-speed bypass channels. The results align closely with theoretical expectations and serve as a robust foundation for future optimization and experimental correlation.

Bypass Duct, Secondary Airflow, Jet Engine Cooling, Computational Fluid Dynamics, Curved Duct Flow, Turbulence Modeling, Compressible Flow, Thermal Management.

"Design and Application of a Bypass Secondary Flow Duct for Jet Engine Cooling Systems", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.12, Issue 6, page no.h351-h360, June-2025, Available :http://www.jetir.org/papers/JETIR2506745.pdf

"Design and Application of a Bypass Secondary Flow Duct for Jet Engine Cooling Systems", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.12, Issue 6, page no. pph351-h360, June-2025, Available at : http://www.jetir.org/papers/JETIR2506745.pdf