High-pumping, high-efficiency fan with forward-swept blades

A vehicle fan assembly for circulating air to cool an engine, said fan assembly comprising:

• a central hub;
• and
• a plurality of blades each with a root joined to said hub, a tip, a span between said root and said tip, a planform having a forward sweep angle continuously increasing in absolute value along said span from said root to said tip, and an airfoil, said blades extending generally radially outward from said hub and each said airfoil having a pitch angle defining three, separate regions:
• (a) a first region in which said pitch angle continuously decreases from said root to about the 1/2-span location,
• (b) a second region in which said pitch angle continuously increases from about the 1/2-span location to about the 7/8-span location, and
• (c) a third region in which said pitch angle continuously decreases from about the 7/8-span location to said tip.

A vehicle fan assembly for circulating air to cool an engine, said fan assembly comprising:

• a central hub;
• and
• a plurality of blades each with a root joined to said hub, a tip, a span between said root and said tip, a planform having a forward sweep angle continuously increasing in absolute value along said span from said root to a maximum absolute value not exceeding about 15 degrees at said tip, and an airfoil, said blades extending generally radially outward from said hub;
• each said airfoil having a chord that continuously increases from said root to said tip, a maximum camber that continuously decreases from a value not greater than about 12% of chord at said root to a value not less than about 5% of chord at said tip, a solidity not greater than about 1.1 at said root and not less than about 0.5 at said tip, and a pitch angle defining three, separate regions:
• (a) a first region in which said pitch angle continuously decreases from said root, where said pitch angle has a value not exceeding about 120% of the tip pitch angle, to about the 1/2-span location,
• (b) a second region in which said pitch angle continuously increases from about the 1/2-span location, where said pitch angle has a value not less than about 80% of the tip pitch angle, to about the 7/8-span location, and
• (c) a third region in which said pitch angle continuously decreases from about the 7/8-span location, where said pitch angle has a value not exceeding about 105% of the tip pitch angle, to said tip.