An optimised stability model for the magnetohydrodynamic fluid

Pramana ◽  
2021 ◽  
Vol 95 (1) ◽  
Author(s):  
Zakir Hussain ◽  
Raja Zeesahan ◽  
Muhammad Shahzad ◽  
Mehboob Ali ◽  
Faisal Sultan ◽  
...  
2010 ◽  
Vol 13 (11) ◽  
pp. 1033-1037
Author(s):  
Muhammad R. Mohyuddin ◽  
S. Islam ◽  
A. Hussain ◽  
A. M. Siddiqui

Author(s):  
Alptunc Comak ◽  
Orkun Ozsahin ◽  
Yusuf Altintas

High-speed machine tools have parts with both stationary and rotating dynamics. While spindle housing, column, and table have stationary dynamics, rotating parts may have both symmetric (i.e., spindle shaft and tool holder) and asymmetric dynamics (i.e., two-fluted end mill) due to uneven geometry in two principal directions. This paper presents a stability model of dynamic milling operations with combined stationary and rotating dynamics. The stationary modes are superposed to two orthogonal directions in rotating frame by considering the time- and speed-dependent, periodic dynamic milling system. The stability of the system is solved in both frequency and semidiscrete time domain. It is shown that the stability pockets differ significantly when the rotating dynamics of the asymmetric tools are considered. The proposed stability model has been experimentally validated in high-speed milling of an aluminum alloy with a two-fluted, asymmetric helical end mill.


Procedia CIRP ◽  
2012 ◽  
Vol 4 ◽  
pp. 90-97 ◽  
Author(s):  
Zoltan Dombovari ◽  
Jokin Munoa ◽  
Gabor Stepan

2004 ◽  
Vol 43 (1-2) ◽  
pp. 25-34 ◽  
Author(s):  
Faruk Civan ◽  
Ludy J Alarcon ◽  
Samuel E Campbell

2017 ◽  
Vol 24 (5) ◽  
pp. 056103 ◽  
Author(s):  
J. W. Berkery ◽  
S. A. Sabbagh ◽  
R. E. Bell ◽  
S. P. Gerhardt ◽  
B. P. LeBlanc

2021 ◽  
Vol 152 (A2) ◽  
Author(s):  
A G W Williams ◽  
M Collu ◽  
M H Patel

The need for high-speed high-payload craft has led to considerable efforts within the marine transport industry towards a vehicle capable of bridging the gap between conventional ships and aircraft. One such concept uses the forward motion of the craft to create aerodynamic lift forces on a wing-like superstructure and hence, reduce the displacement and skin friction. This paper addresses the specific aerodynamic design of multihull for optimal lift production and shows that significant efficiency can be achieved through careful shaping of a ducted hull, with lift-to-drag ratios of nearly 50 for a complete aerodynamic hull configuration. Further analysis is carried out using a hybrid vehicle stability model to determine the effect of such aerodynamic alleviation on a theoretical planing hull. It is found that the resistance can be halved for a fifty metre, three hundred tonne vehicle with aerodynamic alleviation travelling at 70 knots. Results are presented for a candidate vessel.


2021 ◽  
Vol 5 (3) ◽  
pp. 1475-1491
Author(s):  
Gisele Marilha Pereira Reginatto ◽  
Regiane Mara Sbroglia ◽  
Camilo Andrade Carreño ◽  
Bianca Rodrigues Schvartz ◽  
Pâmela Betiatto ◽  
...  

In translational landslide susceptibility analysis with SHALSTAB (Shallow Landsliding Stability Model), the resolution of the digital elevation model (DSM) is determinant for defining the type of mapping generated (preliminary or not). In this study, in order to verify the influence of the SDM scale on the SHALSTAB stability classes, susceptibility maps were prepared at two scales: 1:50,000 and 1:10,000. The study area was the Garcia River watershed, belonging to the municipality of Blumenau, Santa Catarina, affected by landslides in the 2008 catastrophe, which enabled the validation of the simulations with the scars mapped in the field. Thus, the influence of scale on the distribution of the model's stability classes and on its performance was verified. SHALSTAB performed better at the 1:10,000 scale, predicting 70% of the instabilities in a percentage of unstable area approximately three times smaller than at the 1,50,000 scale.


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