1. Flow performance: Long blades should have good flow performance to reduce frictional losses and centrifugal force experienced by the fluid passing through them.
2. Mechanical properties: Long blades should have high strength and wear resistance to withstand pressure and friction at high temperatures and speeds.
3. Thermodynamic properties: Long blades should have good thermal conductivity to allow for rapid heat dissipation in high-temperature environments, preventing deformation and melting.
4. Manufacturing process: The manufacturing process for long blades should be advanced to ensure blade precision and surface quality.