Low camber microfan
A cooling fan comprises an impeller which includes a plurality of radially extending blades, each of which includes a blade hub, a blade tip and a blade midspan approximately midway between the hub and the tip. In addition, each blade comprises a blade suction surface, and substantially the entire blade suction surface is visible from the forward looking aft direction.
1. A cooling fan which comprises:
an impeller which includes a plurality of radially extending blades, each of which includes a blade hub, a blade tip and a blade midspan approximately midway between the hub and the tip;
wherein each blade comprises a blade suction surface;
wherein substantially the entire blade suction surface is visible from the forward looking aft direction; and
wherein each blade comprises a camber of between about 52° and 62° at the blade hub, between about 45° and 56° at the blade midspan and between about 28° and 38° at the blade tip.
2. The cooling fan of claim 1 , wherein no two adjacent blades overlap when viewed in the forward looking aft direction.
3. The cooling fan of claim 1 , wherein the impeller comprises eight blades and wherein the tangential distance between each blade and an adjacent blade is at least about 0.05 inch.
4. The cooling fan of claim 1 , wherein each blade comprises a camber of between about 54° and 59° at the blade hub, between about 49° and 54° at the blade midspan and between about 31° and 36° at the blade tip.
5. The cooling fan of claim 1 , wherein each blade comprises a stagger of between about 19° and 29° at the blade hub, between about 36° and 46° at the blade midspan and between about 47° and 57° at the blade tip.
6. The cooling fan of claim 5 , wherein each blade comprises a stagger of between about 22° and 27° at the blade hub, between about 39° and 44° at the blade midspan and between about 50° and 55° at the blade tip.
7. The cooling fan of claim 1 , wherein each blade comprises a solidity of between about 1.6 and 2.0 at the blade hub, between about 1.15 and 1.55 at the blade midspan and between about 0.85 and 1.25 at the blade tip.
8. The cooling fan of claim 7 , wherein each blade comprises a solidity of between about 1.7 and 1.95 at the blade hub, between about 1.25 and 1.45 at the blade midspan and between about 0.95 and 1.15 at the blade tip.
9. The cooling fan of claim 1 , wherein each blade comprises a normalized chord of about 1.0 at the blade hub, between about 0.95 and 1.1 at the blade midspan and between about 0.85 and 1.25 at the blade tip.
10. The cooling fan of claim 9 , wherein each blade comprises a normalized chord of about 1.0 at the blade hub, between about 0.95 and 1.00 at the blade midspan and between about 0.95 and 1.05 at the blade tip.
11. The cooling fan of claim 1 , wherein each blade includes a leading edge which comprises a lean angle of between about −13° and −8°, a bow angle at the blade hub of between about −2° and 3° and a bow angle at the blade tip of between about 0° and 5°.
12. The cooling fan of claim 11 , wherein each blade includes a trailing edge which comprises a lean angle of between about 12° and 17°, a bow angle at the blade hub of between about 11° and 16° and a bow angle at the blade tip of between about 21° and 26°.
13. The cooling fan of claim 1 , further comprising:
an outlet guide vane assembly which includes a plurality of radially extending guide vanes, each of which comprises a vane hub, a vane tip and a vane midspan approximately midway between the vane hub and the vane tip;
wherein each blade comprises a vane suction surface; and
wherein substantially the entire vane suction surface is visible from the forward looking aft direction.
14. The cooling fan of claim 13 , wherein each guide vane comprises a camber of between about 38° and 48° at the vane hub, between about 32° and 42° at the vane midspan and between about 36° and 46° at the vane tip.
15. The cooling fan of claim 13 , wherein each guide vane comprises a stagger of between about 16° and 26° at the vane hub, between about 11° and 21° at the vane midspan and between about 13° and 23° at the vane tip.
16. The cooling fan of claim 13 , wherein each guide vane comprises a solidity of between about 1.2 and 2.2 at the vane hub, between about 1.0 and 2.0 at the vane midspan and between about 0.8 and 1.8 at the vane tip.
17. The cooling fan of claim 13 , wherein each guide vane comprises a normalized chord of about 1.0 at the vane hub, between about 0.95 and 1.05 at the vane midspan and between about 0.95 and 1.05 at the blade tip.
18. A cooling fan which comprises:
an outlet guide vane assembly which includes a plurality of radially extending guide vanes, each of which comprises a vane hub, a vane tip and a vane midspan approximately midway between the vane hub and the vane tip;
wherein each blade comprises a vane suction surface;
wherein substantially the entire vane suction surface is visible from the forward looking aft direction; and
wherein each guide vane comprises a camber of between about 38° and 48° at the vane hub, between about 32° and 42° at the vane midspan and between about 36° and 46° at the vane tip.
19. The cooling fan of claim 18 , wherein each guide vane comprises a camber of between about 40° and 45° at the vane hub, between about 35° and 40° at the vane midspan and between about 38° and 43° at the vane tip.
20. The cooling fan of claim 18 , wherein each guide vane comprises a stagger of between about 16° and 26° at the vane hub, between about 11° and 21° at the vane midspan and between about 13° and 23° at the vane tip.
21. The cooling fan of claim 20 , wherein each guide vane comprises a stagger of between about 18° and 23° at the vane hub, between about 13° and 18° at the vane midspan and between about 15° and 20° at the vane tip.
22. The cooling fan of claim 18 , wherein each guide vane comprises a solidity of between about 1.2 and 2.2 at the vane hub, between about 1.0 and 2.0 at the vane midspan and between about 0.8 and 1.8 at the vane tip.
23. The cooling fan of claim 22 , wherein each guide vane comprises a solidity of between about 1.5 and 2.0 at the vane hub, between about, 1.2 and 1.6 at the vane midspan and between about 1.0 and 1.4 at the vane tip.
24. The cooling fan of claim 18 , wherein each guide vane comprises a normalized chord of about 1.0 at the vane hub, between about 0.95 and 1.05 at the vane midspan and between about 0.95 and 1.05 at the blade tip.
25. The cooling fan of claim 24 , wherein each guide vane comprises a chord of about 1.0 at the vane hub, between about 0.96 and 1.01 at the vane midspan and between about 0.98 and 1.03 at the blade tip.
26. The cooling fan of claim 18 , wherein each guide vane includes a leading edge which comprises a lean angle of between about −1° and 4°, a bow angle at the vane hub of between about 1° and 6° and a bow angle at the vane tip of between about 3° and 8°.
27. The cooling fan of claim 26 , wherein each guide vane includes a trailing edge which comprises a lean angle of between about 15° and 25°, a bow angle at the vane hub of between about 0° and 10° and a bow angle at the vane tip of between about 5° and 15°.
28. The cooling fan of claim 18 , further comprising:
an impeller which includes a plurality of radially extending blades, each of which includes a blade hub, a blade tip and a blade midspan approximately midway between the hub and the tip;
wherein each blade comprises a blade suction surface; and
wherein substantially the entire blade suction surface is visible from the forward, looking aft direction.
29. The cooling fan of claim 28 , wherein no two adjacent blades overlap when viewed in the forward looking aft direction.
30. The cooling fan of claim 28 , wherein each blade comprises a camber of between about 52° and 62° at the blade hub, between about 45° and 56° at the blade midspan and between about 28° and 38° at the blade tip.
31. The cooling fan of claim 28 , wherein each blade comprises a stagger of between about 19° and 29° at the blade hub, between about 36° and 46° at the blade midspan and between about 47° and 57° at the blade tip.
32. The cooling fan of claim 28 , wherein each blade comprises a solidity of between about 1.6 and 2.0 at the blade hub, between about 1.15 and 1.55 at the blade midspan and between about 0.85 and 1.25 at the blade tip.
33. The cooling fan of claim 28 , wherein each blade comprises a normalized chord of about 1.0 at the blade hub, between about 0.95 and 1.1 at the blade midspan and between about 0.85 and 1.25 at the blade tip.