Will be present at International Conference on Marine Technology 2010 (MARTEC 2010)
11-12 December,2010 Dhaka, Bangladesh
AUTHOR: Adi Maimun, Agoes Priyanto, Noverdo Saputra
ABSTRACT
Longitudinal stability of Wing in Ground Effect Craft (WIG) is still the main concern of WIG craft designers and solutions are being sorted out to reduce this effect. In this research, investigations were conducted to determine the effect of flat ground and end plate proximity on the aerodynamic characteristics and stability criteria of NACA 6409 rectangular wing. The investigation were performed using vortex lattice method and examining the effects of flat ground and endplate on the performance of a trimaran WIG for relative ground clearances of 0.06 < h/c < 0.3, ratio endplate he/c = 0.1 on angles of attack between 0 and 8°, aspect ratio 1< AR < 2 Data is presented for lift coefficient with or without endplate, and static stability margin (SSM) versus angle of attack, and ground clearance. The result of the computation shows that the SSM was significantly affected with changing ground clearances with or without endplate. The results were also compared with experimental & CFD data from another research work.
Keywords: WIG trimaran, Longitudinal Stability, NACA 6409, vortex lattice method, endplate, ground effect
Conclusion
In this work, traditional Vortex Lattice Method (VLM) has been modified by using much complex Flat Wing Theory [7] and then Wielselsberger Ground Effect Theory [2] has been used to calculate lift coefficient In Ground Effect (IGE). The results show values of Lift Coefficient (CL) are more close to experimental results for Angle of Attack (AOA) larger than 2 deg for different Aspect Ratio (AR) and Ground Clearances. Researchers suggest this procedure can be followed for initial estimation of Lift Coefficient for complex wing platform WIG.
It can be shown that using End Plate on the tip wing increases lift coefficient but reduces SSM. On this note, perhaps smart configuration of tail can solve this paradox which could be investigated later.
Full Paper : you can request after conference at verdokapal@yahoo.com
