scholarly journals PERILAKU CHAOS ALIRAN FLUIDA BERDENYUT DALAM SALURAN BERPENAMPANG SEGIEMPAT

2021 ◽  
Vol 4 ◽  
pp. 104-111
Author(s):  
Prayitno Ciptoadi ◽  
Mesak F. Noya ◽  
Gertruida S. Norimarna
Keyword(s):  
Fluid Flow ◽  
Cross Section ◽  
Research Result ◽  
Fluid Flows ◽  
Wheatstone Bridge ◽  
Reynold Number ◽  
Bottom Surface ◽  
Flow Oscillation ◽  
Chaotic Flows

The pulsatile fluid flow in a transverse grooved channel would become chaotic flows in low Reynold numbers. The Reynold number where flows become chaos depends on grooves distances. The objective of this research is to analyze the effect of grooves distances on the behavior of chaos. This research was done by implementing a closed square cross-section channel, where the bottom surface of the channel was semicircle grooved. The frequency of flow oscillation measurement was done by setting up a resistance sensor that is Wheatstone bridge where the resistance sensor was located in a U manometer. Measurement was done at several Reynold number. From the research result, it is seen that the periodic fluid flows in the transverse grooved channel had become chaos at Reynold number Re 950 in the channel without grooved and at Reynold number Re 700 in the grooved channel. Chaos took placed since a vortex appeared at every treatment.

scholarly journals PENGARUH JARAK ALUR TERHADAP KESTABILAN ALIRAN FLUIDA BERDENYUT DALAM SALURAN BERPENAMPANG SEGIEMPAT

2021 ◽  
Vol 1 ◽  
pp. 74-79
Author(s):  
Prayitno Ciptoadi
Keyword(s):  
Fluid Flow ◽  
Cross Section ◽  
Oscillatory Flow ◽  
Phase Plane ◽  
Research Result ◽  
Reynold Number ◽  
Bottom Surface ◽  
Flow Oscillation ◽  
Vortex Strength ◽  
The Stability

The pulsatile fluid flow in a transverse grooved channel would become self-sustained oscillatory flow at a certain critical Reynold number. The critical Reynold number where laminar unsteady flow changed to unsteady transitional one depends on grooves distances. The objective of this research is to analyze the effect of grooves distances toward the vortex strength and the stability of the fluid flow. This research was done by implementing a closed square cross-section channel, where the bottom surface of the channel was semicircle grooved. The frequency of flow oscillation measurement was done by setting up a resistance manometer and measurement was done at several Reynold numbers. From the research result, it is seen that the largest vortex strength occurs at the smallest groove distance. The flows become instability in all of the grooves distances by seen Phase Plane.

scholarly journals Numerical Study on the Characteristics of Air Flows through Helmet Bicycle Racing Using the Effect of Variation of Trailing Edge

2021 ◽  
Vol 6 (1) ◽  
pp. 53-58
Author(s):  
Syamsuri Syamsuri ◽  
Hasan Syafik Maulana ◽  
Achmad Syarifuddin
Keyword(s):  
Fluid Flow ◽  
Drag Force ◽  
Numerical Study ◽  
Research Result ◽  
Time Trial ◽  
Reynold Number ◽  
The Body ◽  
Maximum Speed ◽  
Trailing Edge ◽  
Bicycle Racing

Research on aerodynamics on racing bicycles always develops from time to time. The various geometry of a time-trial helmet produces different characteristics of fluid flow, this is due to the relative movements of air that are in the area throughout the body shape of the helmet. Basically the fluid flow that passes on a racing bicycle helmet will produce a drag force, where this must be minimized in order to hinder the pace of drivers to achieve maximum speed, so drivers should pay attention to how to design the geometry of helmet that should be used. Computational fluid dynamics (CFD) method is used to simulate the case studies in this research. In this study, four kinds of models trailing edge geometry was varied to determine where the most optimal in accepting the drag force. The validation was also conducted to determine the suitability of this study with prior research, where in this validation the results of this study are compared with the research owned (Sims and Jenkins, 2011). The results of this validation show that the resulting drag coefficient has a very small difference of 0.001. The four models are simulated with Reynold number values of 7.14 × 104, 1.00 × 105, and 1.16 × 105. The results of this study indicate that with differences in the geometry of the trailing edge affect the drag force that occurs. From the research result when Reynold 7.0 x 10 ^ 4, the drag force produced by model 3 is bigger than model 1 and 2 which is equal to 0.182 N. Whereas on Reynold which is bigger 1.16 x 10 ^ 5 model 3 receives drag smaller than model 1 and 2 which is equal to 0.283 N.  In the world of bicycle racing, the difference in the small drag force affects the speed of the bicycle and affects the resulting victory.

Lattice-BGK Methods for Simulating Incompressible Fluid Flows

1997 ◽  
Vol 08 (04) ◽  
pp. 793-803 ◽  
Author(s):  
Yu Chen ◽  
Hirotada Ohashi
Keyword(s):  
Fluid Flow ◽  
Incompressible Fluid ◽  
Poisson Equation ◽  
General Model ◽  
Incompressible Flows ◽  
Fluid Flows ◽  
Incompressible Limit ◽  
Numerical Example ◽  
Incompressible Fluid Flows

The lattice-Bhatnagar-Gross-Krook (BGK) method has been used to simulate fluid flow in the nearly incompressible limit. But for the completely incompressible flows, two special approaches should be applied to the general model, for the steady and unsteady cases, respectively. Introduced by Zou et al.,1 the method for steady incompressible flows will be described briefly in this paper. For the unsteady case, we will show, using a simple numerical example, the need to solve a Poisson equation for pressure.

Calculation of hydraulic resistivity coefficients for turbulent fluid flow in channels of noncircular cross section

1967 ◽  
Vol 23 (4) ◽  
pp. 1042-1047 ◽  
Author(s):  
M. Kh. Ibragimov ◽  
I. A. Isupov ◽  
L. L. Kobzar' ◽  
V. I. Subbotin
Keyword(s):  
Fluid Flow ◽  
Cross Section ◽  
Turbulent Fluid Flow ◽  
Turbulent Fluid ◽  
Noncircular Cross Section

A Suction Device Using Air Under Pressure

1956 ◽  
Vol 23 (2) ◽  
pp. 269-272
Author(s):  
L. F. Welanetz
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Fluid Flows ◽  
Central Hole ◽  
Fluid Flow Rate ◽  
Circular Plates ◽  
Suction Device ◽  
Holding Power ◽  
Plate Separation

Abstract An analysis is made of the suction holding power of a device in which a fluid flows radially outward from a central hole between two parallel circular plates. The holding power and the fluid flow rate are determined as functions of the plate separation. The effect of changing the proportions of the device is investigated. Experiments were made to check the analysis.

Modeling of the Ionized Fluid Flow through a Cone-Shaped Nanopore

2007 ◽  
Vol 121-123 ◽  
pp. 1089-1092 ◽  
Author(s):  
Jian Zhong Fu ◽  
Xiao Bing Mi ◽  
Yong He ◽  
Zi Chen Chen
Keyword(s):  
Fluid Flow ◽  
Theoretical Analysis ◽  
Cross Section ◽  
Debye Length ◽  
Velocity Profiles ◽  
Gradual Change ◽  
Ion Flow ◽  
Flow Through

Theoretical analysis of the ionized fluid flowing through a cone-shaped nanopore is presented. The internal cross section of the cone-shaped channel is in the range from micro- to nanometer and gradual change from larger to smaller than the Debye length for the ions. The model is developed to predict the ionized fluid flow behaviors in cone-shaped micro/nanochannels. The velocity profiles of ion flow that occur in nanopores are obtained.

scholarly journals Numerical Investigation on Fluid Flow in a 90-Degree Curved Pipe with Large Curvature Ratio

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Yan Wang ◽  
Quanlin Dong ◽  
Pengfei Wang
Keyword(s):  
Fluid Flow ◽  
Internal Flow ◽  
Fluid Flows ◽  
Detached Eddy Simulation ◽  
Number Range ◽  
Curvature Ratio ◽  
Large Curvature ◽  
Curved Pipe ◽  
Eddy Simulation ◽  
Curved Pipes

In order to understand the mechanism of fluid flows in curved pipes, a large number of theoretical and experimental researches have been performed. As a critical parameter of curved pipe, the curvature ratioδhas received much attention, but most of the values ofδare very small (δ<0.1) or relatively small (δ≤0.5). As a preliminary study and simulation this research studied the fluid flow in a 90-degree curved pipe of large curvature ratio. The Detached Eddy Simulation (DES) turbulence model was employed to investigate the fluid flows at the Reynolds number range from 5000 to 20000. After validation of the numerical strategy, the pressure and velocity distribution, pressure drop, fluid flow, and secondary flow along the curved pipe were illustrated. The results show that the fluid flow in a curved pipe with large curvature ratio seems to be unlike that in a curved pipe with small curvature ratio. Large curvature ratio makes the internal flow more complicated; thus, the flow patterns, the separation region, and the oscillatory flow are different.

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