OS22-9 Analysis of Drag Force on a Sphere Influenced by Other Objects Indirectly(Fluid Flow and Hydrodynamic Forces,OS22 Experimental method in fluid mechanics,FLUID AND THERMODYNAMICS)

2015 ◽  
Vol 2015.14 (0) ◽  
pp. 273
Author(s):  
Tatsuya Kawaguchi ◽  
Ryosuke Takagi ◽  
Sohei Ueda
Keyword(s):  
Fluid Flow ◽  
Fluid Mechanics ◽  
Experimental Method ◽  
Drag Force ◽  
Hydrodynamic Forces

Fluid–Structure Interaction of High Aspect-Ratio Hair-Like Micro-Structures Through Dimensional Transformation Using Lattice Boltzmann Method

2016 ◽  
Vol 08 (08) ◽  
pp. 1650095 ◽  
Author(s):  
H. Devaraj ◽  
Kean C. Aw ◽  
E. Haemmerle ◽  
R. Sharma
Keyword(s):  
Fluid Flow ◽  
Drag Force ◽  
Lattice Boltzmann ◽  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Structural Response ◽  
Momentum Exchange ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Micro Structures

3D printed hair-like micro-structures have been previously demonstrated in a novel micro-fluidic flow sensor aimed at sensing air flows down to rates of a few milliliters per second. However, there is a lack of in-depth understanding of the structural response of these ‘micro-hairs' under a fluid flow field. This paper demonstrates the use of lattice Boltzmann methods (LBM) to understand this structural response towards a better optimization of the micro-hair flow sensors designed to suit the end applications' needs. The LBM approach was chosen as an efficient alternative to simulate Navier–Stokes equations for modeling fluid flow around complex geometries primarily for improved accuracy and simplicity with lesser computational costs. As the spatial dimensions of the sensor's flow channel are much larger in comparison to the actual micro-hairs (the sensing element), a multidimensional approach of combining two-dimensional (D2Q9) and three-dimensional (D3Q19) lattice configurations were implemented for improved computational speeds and efficiency. The drag force on the micro-hairs was estimated using the momentum-exchange method in the D3Q19 configuration and this drag force is transferred to the structural analysis model which determines the micro-hair deformation using Euler–Bernoulli beam theory. The entirety of the LBM Fluid–Structure Interaction (FSI) model was implemented within MATLAB and the obtained results are compared against the numerical model implemented on a commercially available software package.

Stability analysis on dual solutions of second- grade fluid flow with heat and mass transfers over a stretching sheet

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
D. Dey ◽  
R. Borah
Keyword(s):  
Fluid Flow ◽  
Stability Analysis ◽  
Lorentz Force ◽  
Drag Force ◽  
Dual Solutions ◽  
Second Grade ◽  
Second Grade Fluid ◽  
Independent Case ◽  
Grade Fluid ◽  
Mass Transfers

Stability on dual solutions of second-grade fluid flow over a stretching surface with simultaneous thermal and mass diffusions has been studied. The fluid flow is governed by Lorentz force and energy dissipation due to viscosity. Lorentz force is generated due to the application of magnetic field along the transverse direction. In methodology, suitable similarity transformation and MATLAB built-in bvp4c solver technique have been adopted. Effects of some flow parameters are exhibited through figures and tables and a special emphasis is given on the existence of dual solutions. A stability analysis is executed to determine the stable and physically achievable solutions. For the laminar flow, the drag force on the surface for the time-independent case is reduced due to amplifying values of But, it enhances the drag force for the time-dependent case. This shows the effectiveness of the first solution (during steady case) over the unsteady case.

Drag Forces on, and Deformation of, Closed Flexible Bags

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Pål Lader ◽  
David W. Fredriksson ◽  
Zsolt Volent ◽  
Jud DeCew ◽  
Trond Rosten ◽  
...  
Keyword(s):  
Drag Force ◽  
Hydrodynamic Forces ◽  
Towing Tank ◽  
Drag Forces ◽  
Uniform Current ◽  
Salmon Production

The use of closed flexible bags is among the suggestions considered as a potential way to expand the salmon production in Norway. Few ocean structures exist with large, heavily compliant submerged components, and there is presently limited existing knowledge about how aquaculture systems with flexible closed cages will respond to external sea loads. The flexibility and deformation of the bag are coupled to the hydrodynamic forces, and the forces and deformation will be dependent on the filling level of the bag. In order to get a better understanding of the drag forces on, and deformation of, such bags, experiments were conducted with a series of closed flexible bags. The bags were towed in a towing tank in order to simulate uniform current. Four different geometries were investigated, cylindrical, cubical, conical, and pyramidal, and the filling levels were varied between 70% and 120%. The main findings from the experiments were that the drag force was highly dependent on the filling level, and that the drag force increases with decreasing filling level. Comparing the drag force on a deflated bag with an inflated one showed an increase of up to 2.5 times.

scholarly journals Fluid boundaries shaping using the method of kinetic balance

2006 ◽  
Vol 10 (4) ◽  
pp. 153-162
Author(s):  
Miroslav Benisek ◽  
Svetislav Cantrak ◽  
Milos Nedeljkovic ◽  
Djordje Cantrak ◽  
Dejan Ilic ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Fluid Mechanics ◽  
Cross Sections ◽  
Hydraulic Engineering ◽  
Optimum Shape ◽  
Curved Channels ◽  
Unsteady Fluid Flow ◽  
Unsteady Fluid ◽  
Flow Boundaries ◽  
Dead Water

Fluid flow in curved channels with various cross-sections, as a common problem in theoretical and applied fluid mechanics, is a very complex and quite undiscovered phenomenon. Defining the optimum shape of the fluid flow boundaries, which would ensure minimum undesirable phenomena, like "dead water" zones, unsteady fluid flow, etc., is one of the crucial hydraulic engineering?s task. Method of kinetic balance is described and used for this purpose, what is illustrated with few examples. .

scholarly journals The fluid mechanics of poohsticks

2020 ◽  
Vol 378 (2179) ◽  
pp. 20190522 ◽  
Author(s):  
Julyan H. E. Cartwright ◽  
Oreste Piro
Keyword(s):  
Fluid Flow ◽  
Fluid Mechanics ◽  
Solid Body ◽  
State Of The Art ◽  
The State ◽  
Theme Issue ◽  
Two Fluids ◽  
Stokes Drag ◽  
Complex Fluid

The year 2019 marked the bicentenary of George Gabriel Stokes, who in 1851 described the drag—Stokes drag—on a body moving immersed in a fluid, and 2020 is the centenary of Christopher Robin Milne, for whom the game of poohsticks was invented; his father A. A. Milne’s The House at Pooh Corner , in which it was first described in print, appeared in 1928. So this is an apt moment to review the state of the art of the fluid mechanics of a solid body in a complex fluid flow, and one floating at the interface between two fluids in motion. Poohsticks pertains to the latter category, when the two fluids are water and air. This article is part of the theme issue ‘Stokes at 200 (part 2)’.

ANALISIS NILAI HAMBATAN TOTAL DENGAN PERUBAHAN SARAT KAPAL KM. KENDHAGA NUSANTARA 6

2020 ◽  
Vol 21 (1) ◽  
pp. 21-25
Author(s):  
Budi Utomo ◽  
Sulaiman Sulaiman
Keyword(s):  
Fluid Flow ◽  
Experimental Method ◽  
Calculation Method ◽  
Loading Condition ◽  
Total Resistance ◽  
Ship Resistance ◽  
The Difference ◽  
Resistance Value

The calculation of total resistance value is important of ship because  affects the speed of fluid flow that occurs, as well as the speed of the ship.So that in the designing new ships, sea trials are needed to find out whatever the preparedness of the ship is planned. The purpose is to obtain the value of the total resistance and the coefficient of ship resistance KM. Kendhaga Nusantara 6 uses the calculation method for each ship draught/loading condition. The Method used is experimental method with numerical value approach, Denny Mumford theory and Froude's number. The results show that the largest Total Resistance (Rt) is 5646,02 kN, it was found when speed of ship was 12 knots and draught ship 3,5 meters, with a coefficient value (Ct) of 7,757 x 10-3. The difference in value (Ct) is 0,032x10-3 or 0.41%, and it is still in the criteria because it is below 5%.

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