Ünker, F.; Çuvalcı, O.

In this paper, a symmetric gyro with coupling to the tip mass of a beam mounted on a vibrating base is considered. Taking advantage of the angular momentum of the rotating gyroscope, gyrostabilizer systems are expected to become more widely actualized as they provide an effective means of motion control with several significant advantages for various structures. This paper mainly focused on finding optimized stiffness and damping values that minimize the vibration responses with the derivation of the frequency equations of a special combined gyro-beam system. Correctness of the analytical results is verified by numerical simulations. The comparison with the results from the derivation of the corresponding frequency equations shows that the optimized stiffness and damping values are very accurate.

Ünker, F.; Kaplan, E.; Çuvalcı, O.

Computational fluid dynamics (CFD) is widely used in device design to determine gas flowpatterns and turbulence levels. CFD is also used to simulate particles and droplets, which aresubjected to various forces, turbulence and wall interactions. These studies can now beperformed routinely because of the availability of commercial software containing highquality turbulence and particle models. In order to understand how the gas is brought down towafer, it is necessary to have a knowledge of the gas flow behavior very early in t he designspiral of the Tantalum nitride - Atomic layer deposition ( TaN- ALD) chamber by undertakingparametric investigation of the interaction effect between gas flow and the funnel structure.This paper presents such a parametric investigation on a generic TaN- ALD chamber usingCFD. The results presented have been analyzed for a total of 11 different cases by varyingneck and nozzle angles for a process gas. The gas flow was mainly investigated for the nozzleangles of 4.5 , 9 , 12 and 20 and the film thi ckness results were compared with numericalflow patterns. CFD simulations using the turbulence model in ANSYS Fluent v.13 areundertaken. The parametric study has demonstrated that CFD is a powerful tool to study theproblem of gas flow structure interaction on funnel and is capable of providing a means ofvisualizing the path of the gas under different operating conditions .