Flow resistance of natural grasses, sedges and willows was studied in a laboratory flume. The objective was to investigate, how type, density and placement of vegetation, flow depth and velocity influence friction losses. The plants were studied in various combinations under nonsubmerged and submerged conditions in a total of 350 test runs. The results show large variations in the friction fact...

[1] Dynamical predictions of landslide runout require measurements of the basal friction. Here we present the first seismically determined bounds on the frictional coefficients for three large volcanic landslides. The three landslides (Bezymianny, Russia 1956, Sheveluch, Russia 1964 and Mount St. Helens, USA 1980) have masses that vary by a factor of 5 and were all followed immediately by erupt...

In this paper, robust adaptive NN control is investigated for small form factor hard disk drives which is mainly used in mobile applications. The hysteresis friction nonlinearity from the pivot bearing degrades the servo performance, as hard disk drive servo system operates in track-following mode. To deal with the effect of hysteresis friction nonlinearity, adaptive hysteresis friction compens...

Original scientific paper In this work a new approach considering numerical modelling of waterhammer dissipation and attenuation is proposed. The classical Allievi liquid flow model has been extended with the Brunone unsteady friction model which includes separation of the local and convective unsteady friction factor. A widely-adopted approach in solving this model is treatment of the unsteady...

Large-eddy simulations (LES) of turbulent flow in a smoothwall pipe at Reynolds numbers based on the pipe Radius R and wall friction velocity in the range Reτ = 2,000−2,000,000 are discussed. Using a Reynolds number based on D and the bulkflow velocity, then corresponding values are ReD = 91,800 − 165,000,000. For the LES, the spectral-element code SEMTEX was used combined with the stretched-vo...

This paper discusses a methodology of semi-active structural control using a variable friction damper. The presented algorithm is quite simple and straightforward, in which only the slip level of the friction damper is controlled in response to the interstory response velocity of the damperinstalled story so as to maintain the target constant ductility factor. In conducting control there is adv...