The design of a high-performance centrifugal lift fan for Land Craft Air Cushion (LCAC) was evaluated and optimized using the CRUNCH design optimization framework. Overall objective of this project was to improve efficiency of the lift fan by reducing required shaft power and retaining lift side pressure.
Multiple aspects of the system were modified as a result of this optimization analysis. Blade shape was optimized in all three dimensions and total blade count was reduced as well. In addition, the hub was redesigned to remove separated flow. Finally, the bell mouth shape was changed to reduce flow separation near the leading edge.
The final optimized design was tested in subscale and required lower power than the goal of the program while achieving the lift pressure required. Furthermore, efficiency of the optimized design was higher than the goal of the program.