1. Introduction
The oversea market can be seen to increase to meet the global era of the 21’st century, and the negotiations with various countries. In order to satisfy this demand, the transportation to and from overseas quickly and conveniently is an important way. A typical example among these means of transportation is the airplane. The wings of this airplane are those that have the ability to fly artificially with the air pressure from both sides. The flight principle of airplane is based on the law of gravity. This principle of airplane that can overcome this gravity force and fly in the sky can be seen mainly to be lift, momentum, resistance, and gravity^{[115]}. The most important thing in a plane's flight is its lift. The greatest advantage of airplane's wings is that it generates the greatest force of lift when it flies, indicating that the structure of airplane's wings is the most important element during airplane's analytical simulation process.
2. Analysis Result
2.1 Analysis models
In this study, the wing angles of models A, B and C are 120°, 100° and 160° respectively. After modeling, the CFX analysis was conducted^{[46]}. The structural analysis was carried out to investigate the pressure and speed of the airplane applied by the flow according to the wing angle of the airplane. Fig. 1 shows the design models of A, B and C used in this study.
2.2 Comparison of finite element models A, B and C
In this study, Table 1 shows the number of elements at the meshes of models A, B and C generated through finite element method. Table 2 shows the material property of AL7075T6 on aircraft body used in the study.
2.3 Flow analysis
Each flow area on models A, B and C was designated as the fluid enclosure in box format. The inlet speed of flow was given at 700 km/hr and the outlet pressure was applied at 1 atm. Fig. 2 shows the fluid box enclosures of models A, B and C with meshes.
Fig. 3 shows the contours of magnitude and direction on air flow rate for each model. The highest flow rates at all models are shown in the middle wing of the end wing of the airplane. The highest flow rate at models A, B and C become 320.452 m/s, 319.981 m/s and 320.995 m/s respectively.
Fig. 4 shows the contours indicating air resistance pressure at each model. The air resistance pressures of all three models became the highest on the head side of the airplane.
The highest pressures at models A, B and C become 131857Pa, 132271Pa and 132583Pa respectively. Model C was shown to be the airplane model with the wing angle that is most resistant to air resistance pressure.
Fig. 5 shows the contours about the air resistance pressure of the airplane on the midplane at each model, with the highest pressure of 131857 Pa for model A, 132271 Pa for model B and 132583Pa for model C. This figure shows that model C is an airplane model with the wing angle that is most resistant to air resistance pressure.
Fig. 6 shows the contours drawn with the vectors representing the direction of air flow velocity for each model. The highest flow rate for each model was 297.09 m/s for model A, 302.802 m/s for model B and 301.179 m/s for model C. Model B is shown to be the airplane model with the front wing angle as the fastest air flow rate.
3. Conclusion
In this study, the flow analysis was carried out with the fluid model according to the plane's wing angle. The main conclusions obtained from these analyses are as follows;

The air flow rate of each model was the largest at the rear midwing of the airplane. The air flow rate became 302.995 m/s at model C with the largest wing angle among the three models, so it is believed that the larger the angle of the wing, the greater the flow velocity of the airplane.

The air resistance pressure of each model was found to be the highest pressure in the head of the airplane, regardless of the angle of the wing. Among the three models, the highest pressure of 132583MPa can be seen in the model C where the angle of the airplane wing is the largest. The larger the angle of the airplane wing, the airplane wing is thought to be the best structure to withstand the air resistance pressure.