Chapter 1
Introduction
1.1 What is aerofoil?
Aerofoil is a large stucture which is attached to the airplane. It has curved surfaces designed to give required ratio of lift and drag. It helps to create different aeodynamic forces. The force perpendicular to the motion of aeofoil is lift force. The force parallel to the motion of aerofoil is drag force. 1.2 How it works?
Aerofoil consists of following components:
• Suction surface
• Pressure surface
• Leading edge
• Tailing edge
• Chord line Figure 1 Profile of Aerofoil
Source: (Wikipedia, 2017)
On suction surface high velocity of air and low static pressure is generated. On lower surface low velocity of air and high static pressure is generated. Due to the pressure difference in …show more content…
and Yousefi and Saleh investigated the effects of suction and blowing jet width on the aerodynamic characteristics of a NACA 0012 airfoil. They found that the jet width of about 3.5% ~ 4% of the chord length is optimum for tangential blowing, while for perpendicular blowing smaller jet widths are more efficient.
2.2 Control of flow around a NACA 0012 airfoil with a micro-riblet film by S.-J. Lee , Y.-G. Jang
In the present study they studied about the flow structure of the wake behind a NACA 0012 airfoil covered with a V-shaped micro-riblet film(MRF) has been investigated experimentally. The results were compared with the corresponding results from an identical airfoil covered with a smooth polydimethylsiloxane (PDMS) film of the same thickness.
2.2.1 Experimental apparatus and …show more content…
4 shows the mean streamwise velocity distribution in the longitudinal vertical plane for the MRF- and PDMS-covered airfoils subjected to flow velocities of Re ¼ 1.54 104 and Re ¼ 4.62 104. In all systems, the contours are nearly symmetric with respect to the wake centerline (y ¼ 0). For the case of Re ¼ 1.54 104, at which the drag reduction induced by MRF attachment is maximum, the length of the vortex formation region behind the MRF-covered airfoil is shorter and the wake width is slightly longer, compared with the flow around the smooth airfoil. The end of the vortex formation region is usually determined as the point that has the maximum amount of streamwise velocity fluctuation along the wake centerline. These observations indicate that the riblet grooves trip the laminar flow and recover the velocity deficit more quickly with enhanced entrainment of inviscid flow into the wake
Introduction
1.1 What is aerofoil?
Aerofoil is a large stucture which is attached to the airplane. It has curved surfaces designed to give required ratio of lift and drag. It helps to create different aeodynamic forces. The force perpendicular to the motion of aeofoil is lift force. The force parallel to the motion of aerofoil is drag force. 1.2 How it works?
Aerofoil consists of following components:
• Suction surface
• Pressure surface
• Leading edge
• Tailing edge
• Chord line Figure 1 Profile of Aerofoil
Source: (Wikipedia, 2017)
On suction surface high velocity of air and low static pressure is generated. On lower surface low velocity of air and high static pressure is generated. Due to the pressure difference in …show more content…
and Yousefi and Saleh investigated the effects of suction and blowing jet width on the aerodynamic characteristics of a NACA 0012 airfoil. They found that the jet width of about 3.5% ~ 4% of the chord length is optimum for tangential blowing, while for perpendicular blowing smaller jet widths are more efficient.
2.2 Control of flow around a NACA 0012 airfoil with a micro-riblet film by S.-J. Lee , Y.-G. Jang
In the present study they studied about the flow structure of the wake behind a NACA 0012 airfoil covered with a V-shaped micro-riblet film(MRF) has been investigated experimentally. The results were compared with the corresponding results from an identical airfoil covered with a smooth polydimethylsiloxane (PDMS) film of the same thickness.
2.2.1 Experimental apparatus and …show more content…
4 shows the mean streamwise velocity distribution in the longitudinal vertical plane for the MRF- and PDMS-covered airfoils subjected to flow velocities of Re ¼ 1.54 104 and Re ¼ 4.62 104. In all systems, the contours are nearly symmetric with respect to the wake centerline (y ¼ 0). For the case of Re ¼ 1.54 104, at which the drag reduction induced by MRF attachment is maximum, the length of the vortex formation region behind the MRF-covered airfoil is shorter and the wake width is slightly longer, compared with the flow around the smooth airfoil. The end of the vortex formation region is usually determined as the point that has the maximum amount of streamwise velocity fluctuation along the wake centerline. These observations indicate that the riblet grooves trip the laminar flow and recover the velocity deficit more quickly with enhanced entrainment of inviscid flow into the wake