Park S.,TSonNet Co Ltd. |
Baek N.,TSonNet Co Ltd. |
Baek N.,Kyungpook National University
International Journal of Software Engineering and its Applications | Year: 2013
In the typical semi-Lagrangian framework for Navier-Stokes equations, the advection source positions for each grid center points are repeatedly estimated to get interpolated physical quantities. Most research efforts are concentrated on the numerical accuracy, especially for the interpolation of target physical quantities. In this paper, we adopted an improved trajectory integration scheme during the advection calculation process. Our method traces the grid center points using their previous velocities at the previous time step, while other previous methods use their current velocities. Our experimental results show remarkable improvements, and we achieved real-time processing capability even with straight-forward serial implementations.
Park S.,TSonNet Co. |
Baek N.,Kyungpook National University |
Ryu K.-W.,TSonNet Co.
International Journal of Multimedia and Ubiquitous Engineering | Year: 2012
We present a dynamics model of rotor blades for real-time helicopter simulation. Collisions between the air flow and the moving blades make helicopters fly. In aerodynamics, or even in computer simulations, they precisely analyzed the collisions between the fluid(air) and the solid object(blades), and calculated the differential equations from the collisions. Thus, it was hard for them to generate real-time helicopter motions due to massive computations for calculating the equations. In this paper, we start from a geometric model of rotor blades, which reflects the characteristics of real world blades due to the various factors from helicopter aerodynamics, although some factors should be simplified to show real-time behaviors. Based on this geometric model, we present a dynamics model for calculating the forces due to the rotor blades colliding with air flows. Our dynamics model interprets the collisions between the fluid and the solid objects as the action-reaction forces, as originally Newton did. Finally, we present the force equations suitable for the existing rigid-body simulation systems, instead of fluid-dynamics equations. We implement a prototype system for helicopter motions, and it shows sufficient real-time processing behavior with ordinary PC's.