Pneumatic tire

1. A pneumatic tire in which turbulent-flow generating projections each extending from an inner circumference side to an outer circumference side, and provided on an outer tire surface at intervals in a tire circumferential direction, wherein:

each of the turbulent-flow generating projections includes an edge portion when being viewed in a cross-sectional shape taken along a direction perpendicular to an extending direction thereof; and

a front wall angle formed between a front wall face of each turbulent-flow generating projection and the tire surface is set in the range of 70° to 110°, the front wall face being hit by an airflow,

wherein the turbulent-flow generating projections are provided in a tire side portion,

wherein relationships of 8.0≦p/h≦50.0 and 10.0≦(p−w)/w≦50.0 are satisfied where: h denotes the height of each of the turbulent-flow generating projections; p denotes a pitch of adjacent ones of the turbulent-flow generating projections in a tire rotation direction; and w denotes a lower side width of each of the turbulent-flow generating projections in the cross-sectional shape,

wherein the turbulent-flow generating projections are provided at regular intervals in the tire circumferential direction,

wherein the pneumatic tire is a heavy-duty tire specified by the standards determined by The Tire and Rim Association, Inc. Year Book in the United States of America.

2. The pneumatic tire according to claim 1 , wherein the cross-sectional shape of each turbulent-flow generating projection is left-right symmetric.

3. The pneumatic tire according to claim 1 , wherein a rear wall angle formed between a rear wall face and the tire surface is set to 90° or more, the rear wall face being located in the rear of the front wall face with respect to a tire rotation direction.

4. The pneumatic tire according to claim 1 , wherein a lower side width of the cross-sectional shape of the turbulent-flow generating projection is set in the range of 0.5 mm to 5 mm.

5. The pneumatic tire according to claim 1 , wherein a relationship of 0.03≦h/R½≦0.64 is satisfied where: h denotes a height of the turbulent-flow generating projection; and R, a tire radius.

6. The pneumatic tire according to claim 5 , wherein a relationship of 0.05 h/R½≦0.64 is satisfied where: h denotes a height of the turbulent-flow generating projection; and R, a tire radius.

7. The pneumatic tire according to claim 5 , wherein the cross-sectional shape of the turbulent-flow generating projection is trapezoidal.

8. The pneumatic tire according to claim 1 , wherein a through-hole is formed in the turbulent-flow generating projection, the through-hole penetrating in a direction perpendicular to the extending direction.

9. The pneumatic tire according to claim 1 , wherein a tilt angle θ is set in the range of −70°≦θ≦70°, the tilt angle θ being an angle at which the turbulent-flow generating projection tilts to a tire radial direction.

10. The pneumatic tire according to claim 1 , wherein a sidewall reinforcing layer which reinforces the tire side portion is provided in the tire side portion.

11. The pneumatic tire according to claim 1 further comprising a carcass layer inclining at a 90 degree angle with respect to the tire circumferential direction.

12. The pneumatic tire according to claim 1 , wherein the edge portion is formed on the front wall face and an upper face.

13. A pneumatic tire in which turbulent-flow generating projections each extending from an inner circumference side to an outer circumference side, and provided on an outer tire surface at intervals in a tire circumferential direction, wherein:

each of the turbulent-flow generating projections includes an edge portion when being viewed in a cross-sectional shape taken along a direction perpendicular to an extending direction thereof; and

a front wall angle formed between a front wall face of each turbulent-flow generating projection and the tire surface is set in the range of 70° to 110°, the front wall face being hit by an airflow,

wherein the turbulent-flow generating projections are provided in a tire side portion,

wherein relationships of 8.0≦p/h≦50.0 and 10.0≦(p−w)/w≦50.0 are satisfied where: h denotes the height of each of the turbulent-flow generating projections; p denotes a pitch of adjacent ones of the turbulent-flow generating projections in a tire rotation direction; and w denotes a lower side width of each of the turbulent-flow generating projections in the cross-sectional shape,

wherein the turbulent-flow generating projections are provided at regular intervals in the tire circumferential direction,

wherein a relationship of 10.0≦(p−w)/w≦25.0 is satisfied where: p denotes a pitch of adjacent ones of the air turbulent-flow generating projections in a tire rotation direction; and w denotes a lower side width of each of the air turbulent-flow generating projections in the cross-sectional shape.

14. A pneumatic tire in which turbulent-flow generating projections each extending from an inner circumference side to an outer circumference side, and provided on an outer tire surface at intervals in a tire circumferential direction, wherein:

each of the turbulent-flow generating projections includes an edge portion when being viewed in a cross-sectional shape taken along a direction perpendicular to an extending direction thereof; and

a front wall angle formed between a front wall face of each turbulent-flow generating projection and the tire surface is set in the range of 70° to 110°, the front wall face being hit by an airflow,

wherein the turbulent-flow generating projections are provided in a tire side portion,

wherein relationships of 8.0≦p/h≦50.0 and 10.0≦(p−w)/w≦50.0 are satisfied where: h denotes the height of each of the turbulent-flow generating projections; p denotes a pitch of adjacent ones of the turbulent-flow generating projections in a tire rotation direction; and w denotes a lower side width of each of the turbulent-flow generating projections in the cross-sectional shape,

wherein the turbulent-flow generating projections are provided at regular intervals in the tire circumferential direction,

wherein a relationships of 8.0≦p/h≦14.0 is satisfied where: h denotes a height of each of the air turbulent-flow generating projections and p denotes a pitch of adjacent ones of the air turbulent-flow generating projections in a tire rotation direction.