Nagoya Institute of Technology

About: Nagoya Institute of Technology is a education organization based out in Nagoya, Japan. It is known for research contribution in the topics: Thin film & Turbulence. The organization has 10766 authors who have published 19140 publications receiving 255696 citations. The organization is also known as: Nagoya Kōgyō Daigaku & Nitech.

Pressure Spectrum in Homogeneous Turbulence

Abstract: The pressure spectrum in homogeneous steady turbulence is studied using direct numerical simulation with resolution up to 1024(3) and the Reynolds number R(lambda) between 38 and 478. The energy spectrum is found to have a finite inertial range with the Kolmogorov constant K = 1.65+/-0.05 followed by a bump at large wave numbers. The pressure spectrum in the inertial range is found to be approximately P(k) = B(p)epsilon;(4/3)k(-7/3) with B(p) = 8.0+/-0.5, and followed by a bump of nearly k(-5/3) at higher wave numbers. Universality and a new scaling of the pressure spectrum are discussed.

Disturbance observer-based nonlinear friction compensation in table drive system

Abstract: This paper presents a disturbance observer-based algorithm for nonlinear friction compensation in table drive systems to achieve the high accurate trajectory control In order to design an effective compensator, dynamic characteristics of the friction are examined and, as a result, a simple and high accurate observer can be designed on the basis of the analyzed friction characteristic Using the disturbance observer based compensation, the precise velocity/position control can be attained without the response delay which is caused by the restricted control bandwidth in conventional compensation algorithms Experimental results show the significant performance improvement of the proposed algorithm in the trajectory control with low feed rate and velocity reversal motion