This research is a follow-up to the previous research which was dealing with the creation of the simulation of the vocal cords function using FEM. This paper focuses on how the vocal cords function is affected by Bernoulli's effect, while using model [1] is used. It is well known, that Bernoulli's effect is connected with the suction in the air space between the vocal cords. This is caused by the high air flow in glottis. The fastest and easiest way how to eliminate the influence of this effect is the change of every negative air pressure on the vocal cords to zero (i.e. the pressure applied as the loads on the vocal cords). Authors of some vocal cords models presume that Bernoulli's effect is the main force causing vocal cords vibrations. Changing the negative pressures to zero should cause that the vocal cords would not vibrate. However, the results of this research show the opposite. and Obsahuje seznam literatury
The influence of water environment on natural frequencies of a Francis pump-turbine runner with the shaft is analyzed. The computations are executed by ANSYS program package based on finite element method. The fluid ‘equivalent mass‘ matrix concept is used. For solution, the Euler approach is used. Obtained natural frequencies and vibration mode shapes of the turbine runner with shaft in vaccum, in air and in water are presented. Computed natural frequencies and vibration mode shapes of the turbine runner with shaft in vacuum are compared to computed natural frequencies and vibration mode shapes of the turbine runner without shaft. and Obsahuje seznam literatury