Dynamic action of a liquid in an open reservoir undergoing forward motion

1970 ◽  
Vol 6 (1) ◽  
pp. 70-75 ◽  
Author(s):  
V. N. Tishchenko ◽  
Yu. A. Shevlyakov
Keyword(s):  
Forward Motion ◽  
Dynamic Action ◽  
Open Reservoir

Computing Model for Vibratory Digging-Out of Sugar Beet Roots

2014 ◽  
Vol 1 (2) ◽  
pp. 52-60
Author(s):  
V. Bulgakov ◽  
V. Adamchuk ◽  
H. Kaletnyk
Keyword(s):  
Differential Equations ◽  
Sugar Beet ◽  
Vertical Plane ◽  
Forward Motion ◽  
Admissible Velocity ◽  
Beet Root ◽  
Optimum Speed ◽  
Analytical Research ◽  
Sugar Beet Root ◽  
The Given

The new design mathematical model of the sugar beet roots vibration digging-out process with the plowshare vibration digging working part has been created. In this case the sugar beet root is simulated as a solid body , while the plowshare vibration digging working part accomplishes fl uctuations in the longitudinal - vertical plane with the given amplitude and frequency in the process of work . The aim of the current research has been to determine the dependences between the design and kinematic parameters of the sugar beet roots vibra- tion digging-out technological process from soil , which provide the ir non-damage. Methods . For the aim ac- complishment, the methods of design mathematical models constructing based on the classical laws of me- chanics are applied. The solution of the obtained differential equations is accomplished with the PC involve- ment. Results . The differential equations of the sugar beet root’s motion in course of the vibration digging-out have been comprised . They allow to determine the admissible velocity of the vibration digging working part’s forward motion depending on the angular parameters of the latter. In the result of the computational simula- tion i.e., the solution of the obtained analytical dependence by PC, the graphic dependences of the admissible velocity of plowshare v ibration digging working part’s forward motion providing the extraction of the sugar beet root from soil without the breaking-off of its tail section have been determined. Conclusions . Due to the performed analytical research , it has been established that γ = 13 ... 16 ° , β = 20 ... 30 ° should be considered as the most reasonable values of γ and β angles of the vibration digging working part providing both its forward motion optimum speed and sugar beet root digging-out from the soil without damage . On the ground of the data obtained from the analytical rese arch, the new vibration digging working parts for the sugar beet roots have been designed; also the patents of Ukraine for the inventions have been obtained for them.

Dynamic action of keratinase on wool fibre tracked by FITC-labelled enzyme

2020 ◽  
pp. 1-9
Author(s):  
Zhang-Jun Cao ◽  
Xiao-Xiao Song ◽  
Qian Zhu ◽  
Juan Wang ◽  
Run Gong ◽  
...  
Keyword(s):  
Wool Fibre ◽  
Dynamic Action

Dust devils: Characteristics of the forward motion from a Saharan survey

2021 ◽  
Vol 50 ◽  
pp. 100678
Author(s):  
Gabriele Franzese ◽  
Simone Silvestro ◽  
David A. Vaz ◽  
Ciprian Ionut Popa ◽  
Fabio Cozzolino ◽  
...  
Keyword(s):  
Dust Devils ◽  
Forward Motion

Provision of negative feedback in the conditions of working movement of strip saw blades

2021 ◽  
pp. 61-64
Author(s):  
Keyword(s):  
Energy Consumption ◽  
Negative Feedback ◽  
Translational Motion ◽  
Lateral Force ◽  
Forward Motion ◽  
Motion Stability ◽  
Reduce Energy Consumption ◽  
Design Solutions ◽  
Saw Blade

A new solution is proposed for sawing machines with circular translational motion of the saw blades, which eliminates the effect of lateral force on the saw blade. These design solutions increase the accuracy of the resulting lumber, processing productivity, equipment life and reduce energy consumption. Keywords: sawing machine, saw blade, circular forward motion, stability, negative feedback. [email protected], tel. 8 (915)-301-78-74

AERODYNAMIC LIFT FORCES ON MULTIHULLED MARINE VEHICLES

2021 ◽  
Vol 152 (A2) ◽  
Author(s):  
A G W Williams ◽  
M Collu ◽  
M H Patel
Keyword(s):  
High Speed ◽  
Vehicle Stability ◽  
Aerodynamic Design ◽  
Forward Motion ◽  
Marine Vehicles ◽  
Marine Transport ◽  
Stability Model ◽  
Lift Forces ◽  
High Payload ◽  
Aerodynamic Lift

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.

Forward Motion

2017 ◽  
Vol 28 (3) ◽  
pp. 56-63
Author(s):  
Yudhijit Bhattacharjee
Keyword(s):  
Forward Motion

Experimental Investigation of the Submarine Crashback Maneuver

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
David H. Bridges ◽  
Martin J. Donnelly ◽  
Joel T. Park
Keyword(s):  
Vortex Structure ◽  
Thrust Force ◽  
Ring Vortex ◽  
Forward Motion ◽  
Compact Structure ◽  
Moment Coefficient ◽  
Different Types ◽  
Out Of Plane ◽  
Direction Opposite ◽  
Relative Flow

In order to decelerate a forward-moving submarine rapidly, often the propeller of the submarine is placed abruptly into reverse rotation, causing the propeller to generate a thrust force in the direction opposite to the submarine’s motion. This maneuver is known as the “crashback” maneuver. During crashback, the relative flow velocities in the vicinity of the propeller lead to the creation of a ring vortex around the propeller. This vortex has an unsteady asymmetry, which produces off-axis forces and moments on the propeller that are transmitted to the submarine. Tests were conducted in the William B. Morgan Large Cavitation Channel using an existing submarine model and propeller. A range of steady crashback conditions with fixed tunnel and propeller speeds was investigated. The dimensionless force and moment data were found to collapse well when plotted against the parameter η, which is defined as the ratio of the actual propeller speed to the propeller speed required for self-propulsion in forward motion. Unsteady crashback maneuvers were also investigated with two different types of simulations in which propeller and tunnel speeds were allowed to vary. It was noted during these simulations that the peak out-of-plane force and moment coefficient magnitudes in some cases exceeded those observed during the steady crashback measurements. Flow visualization and LDV studies showed that the ring vortex structure varied from an elongated vortex structure centered downstream of the propeller to a more compact structure that was located nearer the propeller as η became more negative, up to η=−0.8. For more negative values of η, the vortex core appeared to move out toward the propeller tip.

scholarly journals A Simple Model for Simulating Tornado Damage in Forests

2006 ◽  
Vol 45 (12) ◽  
pp. 1597-1611 ◽  
Author(s):  
Andrew P. Holland ◽  
Allen J. Riordan ◽  
E. C. Franklin
Keyword(s):  
Simple Model ◽  
Loblolly Pine ◽  
Forward Speed ◽  
Forward Motion ◽  
Tree Resistance ◽  
Forested Areas ◽  
Storm Characteristics ◽  
Tornado Damage ◽  
Cross Track ◽  
Along Track

Abstract An analytical model is presented to describe patterns of downed trees produced by tornadic winds. The model uses a combined Rankine vortex of specified tangential and radial components to describe a simple tornado circulation. A total wind field is then computed by adding the forward motion of the vortex. The lateral and vertical forces on modeled tree stands are then computed and are compared with physical characteristics of Scots and loblolly pine. From this model, patterns of windfall are computed and are compared to reveal three basic damage patterns: cross-track symmetric, along-track asymmetric, and crisscross asymmetric. These patterns are shown to depend on forward speed, radial speed, and tree resistance. It is anticipated that this model will prove to be useful in assessing storm characteristics from damage patterns observed in forested areas.

Sign in / Sign up

Export Citation Format

Share Document