helicopter blade airfoil

Worried about getting the best Helicopter Blade Airfoil? This is a detailed research on helicopter blade design calculations. If your preference is how to make helicopter rotor blades, then this article is perfect for you.

An airfoil is any surface, such as an airplane wing or a helicopter rotor blade, which generates aerodynamic force when it interacts with a moving stream of air. Although there are many different rotor blade airfoil designs, in most helicopter flight conditions, all airfoils perform in the same manner. 

helicopter blade design calculations

Helicopter Blade Airfoil

Early helicopter designs used relatively thick airfoils for their structural characteristics. Because the rotor blades were very long and slender, it was necessary to incorporate more structural rigidity into them. This prevented excessive blade droop when the rotor system was idle, and minimized blade twisting while in flight. The airfoils were also designed to be symmetrical, which means they had the same camber (curvature) on both the upper and lower surfaces. See figure 1-1.
Symmetrical blades are very stable, which helps keep blade twisting and flight control loads to a minimum. This stability is achieved by keeping the center of pressure virtually unchanged as the angle of attack changes. Center of pressure is the imaginary point on the chord line where the resultant of all aerodynamic forces is considered to be concentrated. Modern design use thinner airfoils and obtain the required rigidity by using composite materials. In addition, airfoils are asymmetrical in design, meaning the upper and lower surface do not have the same camber. Normally these airfoils would not be as stable, but this can be corrected through reflexing; bending the trailing edge to produce the same characteristics as symmetrical airfoils. Using this type of rotor blade allows the rotor system to operate at higher forward speeds.
One of the reasons an asymmetrical rotor blade is not as stable is that the center of pressure changes with changes in angle of attack. When the center of pressure lifting force is behind the pivot point on a rotor blade, it tends to cause the rotor disc to pitch up. As the angle of attack increases, the center of pressure moves forward. If it moves ahead of the pivot point, the pitch of the rotor disc decreases. Since the angle of attack of the rotor blades is constantly changing during each cycle of rotation, the blades tend to flap, feather, lead, and lag to a greater degree. The blade span is the distance from the rotor hub to the blade tip. Blade twist refers to a changing chord line from the blade root to the tip. Twisting a rotor blade causes it to produce a more even amount of lift along its span. This is necessary because rotational velocity increases toward the blade tip. 
Fig1-2.JPGThe leading edge is the first part of the airfoil to meet the oncoming air. Relative wind is created by the motion of an airfoil through the air, by the motion of air past an airfoil, or by a combination of the two. Relative wind may be affected by several factors, including the rotation of the rotor blades, horizontal movement of the helicopter, flapping of the rotor blades, and wind speed and direction. See Figure 1-2.
The pitch angle of a rotor blade is the angle between its chord line and the reference plane containing the rotor hub. The pitch angle of the blades is controlled with the flight controls. The collective pitch control changes each rotor blade an equal amount of pitch no matter where the blade is located in the plane of rotation (rotor disc) and is used to change rotor thrust. The cyclic pitch control changes the pitch of each blade as a function of where the blade is in the plane of rotation. This allows for controlling pitch and roll during forward flight and for maneuvering in all flight conditions. See Figure 1-3. See also “helicopter flight controls” course for more details on helicopter flight controls.

Things to keep in mind:Fig1-3.JPG

  • The rotor axis of rotation and the rotor mast are two separate entities. The only time they coincide is when the tip-path plane is perpendicular to the rotor mast.
  • Angle of attack and pitch angle are also two separate entities. Angle of attack is determined by the direction of the relative wind. Angle of attack is determined by changing the pitch angle through the use of the flight controls. If the pitch angle is increased, the angle of attack is increased, if the pitch angle is reduced, the angle of attack is reduced.

how to make helicopter rotor blades

Top 10 Luxury Helicopters in the World

Most people have heard of personal and charter jets, but luxury helicopters are the genuine gems. Not only are these aircraft comparatively less expensive, but helicopters can approach places that bulky jets can’t. Having a private or commercial helicopter is expedient, more environment friendly, and a symbol of status. Celebrities including Brad Pitt and Angelina Jolie and Donald Trump own a luxury helicopter, and this slot market has grown considerably in recent years due to demand from the rich.

They are well-appointed with all the newest technology, and interior seating marks that are designed in fine Italian leather upholstery.

Therefore the list of top 10 luxury helicopters is given below:

1. Augusta Westland AW119 Ke Koala:

luxury helicopters

The Koala is chiefly used by law enforcement, but it can easily provide accommodation to a group of corporate directors traveling on business. It has a VIP services quite adequately, with premium leather upholstery and seating for about 6 passengers and 2 operators. The Koala reaches a top speed of 166 mph (267 km/h) and a range of 618 miles (995 km). Price ranges from $1.8 to $3 million.

2. Eurocopter Hermès EC 135:

luxury helicopters

Though this brand of luxury helicopters is not suitable for long distant trips, is has a class apart built. The typical EC 135 will cost you a mere $4.2 million, but the one with the interior design from the best in class designer will cost you up to $6 million. The top speed is 178 mph, but the range is just 395 miles.

3. Augusta Westland AW109 Grand Versace VIP:

luxury helicopters

Augusta Westland teamed up with the Italian fashion house Versace to produce a super luxury interior for this fancier version of the AW109. The top speed is about 177 mph and a range of 599 miles. The mere difference is that all 599 of those miles will be more luxurious for the VIP passengers. Hence, will cost you $6.3 million price tag and the helicopter is fully covered in Versace leather, design and exterior.

4. Eurocopter Mercedes-Benz EC 145:

luxury helicopters

If you’re a Mercedes fan, now you can fly your preferred brand helicopter too. A regular EC 145 costs about $5.5 million, so the Mercedes version is going to cost anywhere around $7 million. But it’s totally worth it. No other Mercedes can go 153 mph while flying 17,000 feet above the ground. It has all the luxury of the famous German sports.

5. Eurocopter EC 175:

luxury helicopters

The EC 175 made its wonderful first appearance at the Paris Air Show in 2009. The chief feature of the EC 175 is that it can hold 16 passengers contentedly inside. The top speed reaches 178 mph (286 km/h), with a range of 345 miles (555 km). It costs whooping $7.9 million.

6. Eurocopter EC 155:

luxury helicopters

This is a luxurious chopper. Its top speed is an impressive 200 mph with a range of 533 miles. It can seat as many as 13 passengers; this spacious EC 155 aircraft will cost you $10 million.

7. Sikorsky S-76C:

luxury helicopters

The Sikorsky S-76C is more generally known as Black Hawk. The massive interior is large sufficient to fit up to a dozen passengers, but the seating occupies 4 passengers in Black Hawk model. It reaches a top speed of 178 mph (286 km/h) and has a range of 473 miles (761 km). It would cost you a $12.95 million.

8. Augusta Westland AW139:

luxury helicopters

The AW139 is appropriate for law enforcement, armed patrol and firefighters. It has a capacity to seat 8 passengers. The AW139 can reach an unbelievable top speed of 193 mph (310 km/h), with a range of 573 miles (922 km). It carries a beautiful interior costing you a hefty $14.5 million.

9. Bell 525 Relentless:

luxury helicopters

Like the Gulfstream 650 jet, the Bell 525 Relentless helicopter isn’t on the market currently. This chopper is going to cost $15 million. They predicted that the seating will be for 16, a top speed of 162 mph, and a range of 460 miles. This bright yellow Relentless with amazing seating will cost you a fortune.

10. Sikorsky S-92 VIP Configuration:

luxury helicopters

The S-92 can safely accommodate 9 passengers in its extensive interior cabin. The prices vary exponentially if you plan on decking the interiors with gold or crystal. The top speed of the S-92 is around 194 mph (312 km/h), with a range of 594 miles (956 km). The prices range from $17 million to $32 million.
Helicopter charter can be the most stress-free travel familiarity you will ever have. Which includes being able to travel outside of airports to reach vital meetings or even other flights in a different airport. Though rich class can afford these luxury helicopters, they are worth the investment.

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