⊙ Development of Near Future (New Concept) Aircraft:
The performance improvement of recently developed commercial aircraft mainly depends on the improvement of engine performance. The engines of these aircrafts have a relative large engine radius to achieve a high bypass ratio. This trend will be continued for the time being to improve the engine performance. However, the aircraft with a large engine radius will have a ground clearance problem as shown in Fig. 1.
Figure 1. Ground clearance problem.
To eliminate the ground clearance problem of a large radius engine, there is several engine arrangement concepts suggested as shown in Fig. 2.
Figure 2 4-engine configuration, high-wing configuration and real-jet configuration
In this research, we are investigating the aerodynamic performance of high-wing configuration aircraft whose wings are attached to upper part of fuselage. To develop the high performance high-wing aircraft, the computational fluid dynamic (CFD) simulation on supercomputer and advanced design exploration (optimization) method are employed as shown in Fig. 3.
Figure 3. Fully automated mesh generation, parallel computing on supercomputer and high efficient design exploration.
⊙ Development of Mars Exploration Airplane:
Until now, the Mars explorations have been done by ground-based rovers and orbiters. Rovers can provide a high quality data but its exploration area is limited. On the other hand, orbiter can supply a spatially wide data but its resolution is very low. Another method of Mars exploration is using airplane. Airplane can explore a larger area than rover and can supply much higher resolution data than orbiter. However, flight on Mars is very difficult because its atmosphere condition is totally different from that of earth. First, the atmospheric density of Martian surface is roughly equivalent to an altitude of 100,000 feet on Earth. With such a thin atmosphere, generating enough lift to support the airplane weight is difficult and wing loading has to be small. Another problem is that the speed of sound on Mars is lower than on Earth. Thus, transonic aerodynamic effects are encountered at a low flight speed.
The final goal of this research is to develop high performance Mars exploration airplane that can explore the over than 500km area. To achieve this goal, we are developing
Fig 1. Mars Exploration Airplane
Fig 2. Mars Exploration Airplane Deployment
Fig 3. Mars Exploration Airplane in Entry Aeroshell
Fig 4. Intermittency of ss1f(ARES) and Designed Airfoils
Fig 5. Design Result
⊙ Design Knowledge Mining and Big Data Analysis
During the design process using Evolutionary Algorithms, tremendous design data are obtained. From these data, it is possible to extract invaluable knowledge about the design problem. Recently, the process of t is called ‘Data Ming’ or ‘Big Data Analysis’.
For example, there are 1024 hull forms which are obtained through the low drag hull form design. (obj1, obj2 and obj3 are wave drag coefficient at Fn = 0.22, 0.27 and 0.305, respectively). Each gray circle in Fig. 1 corresponds to each hull form.
Figure 1 Design Exploration Results
To analyze these data, we applied ANOVA (Analysis of Variance) and Self-Organizing Map (SOM). The result of ANOVA and SOM are shown in Fig. 2.
<!--[if !supportLists]-->(a) <!--[endif]-->ANOVA
Figure 2 Data Mining with ANOVA and SOM
Based on the information obtained from the data mining, the following design knowledge can be acquired.
(1) A narrower waterline in the bow region (small DV10 and DV11) is a necessary condition for a non-dominated solution.
(2) A wider section shape (large DV4, DV7, DV8, and DV12) is preferable for low-speed performance, while a narrower section shape (small DV4, DV7, DV8, and DV12) is necessary for high-speed performance.