scholarly journals Study on the Behavior of Helmholtz Resonance in Different Size Bottles

2021 ◽  
Vol 4 (1) ◽  
pp. 12-21
Author(s):  
S.K. Adhikari ◽  
B. Sapkota ◽  
S. Dhungana ◽  
P. Pokharel
Keyword(s):  
Experimental Data ◽  
Resonant Frequency ◽  
Musical Instrument ◽  
Specific Response ◽  
Sectional Area ◽  
Cross Sectional ◽  
Open Mouth ◽  
Helmholtz Resonance ◽  
Response Data ◽  
Neck Radius

The resonance is the specific response of system which is capable to vibrate with certain frequency to an external force acting with the same frequency. When air is blown across the open mouth of different bottles then air vibrate in a neck at resonant frequency. In this study we consider 5-5 bottles of different five types bottles having different of length of neck, radius of port, cross-sectional area of port and same volume (250ml). Resonance in different bottles was studied to determine how the volume of air cavity of different bottle affects the resonance. From calculated and experimental data, we found that the Helmholtz resonance frequency decreases with increase in volume and vice versa in each case of different bottles. From graph we also found that the calculated and experimental model are about 100% and 99% variability of the response data around its mean. The practical range for these different bottles is from about 256 to 512 Hz. This is about an octave plus a musical fifth near the middle of the musical instrument, so most simple musical tunes can be produced with such bottles.

scholarly journals Representative subsampling of sedimenting blood

2019 ◽  
Vol 475 (2227) ◽  
pp. 20190223
Author(s):  
Bhargav Rallabandi ◽  
Janine K. Nunes ◽  
Antonio Perazzo ◽  
Sergey Gershtein ◽  
Howard A. Stone
Keyword(s):  
Experimental Data ◽  
Entire Range ◽  
Original Sample ◽  
Sectional Area ◽  
Cross Sectional ◽  
Design Considerations ◽  
Simple Tool ◽  
Sedimentation Model ◽  
Practical Challenge ◽  
Larger Sample

It is often necessary to extract a small amount of a suspension, such as blood, from a larger sample of the same material for the purposes of diagnostics, testing or imaging. A practical challenge is that the cells in blood sediment noticeably on the time scale of a few minutes, making a representative subsampling of the original sample challenging. Guided by experimental data, we develop a Kynch sedimentation model to discuss design considerations that ensure a representative subsampling of blood, from a container of constant cross-sectional area, for the entire range of physiologically relevant hematocrit over a specified time of interest. Additionally, we show that this design may be modified to exploit the sedimentation and perform subsampling to achieve either higher or lower hematocrit relative to that of the original sample. Thus, our method provides a simple tool to either concentrate or dilute small quantities of blood or other sedimenting suspensions.

scholarly journals Numerical Study on the Temperature-Dependent Viscosity Effect on the Strand Shape in Extrusion-Based Additive Manufacturing

2020 ◽  
Vol 4 (2) ◽  
pp. 46 ◽  
Author(s):  
Behrouz Behdani ◽  
Matthew Senter ◽  
Leah Mason ◽  
Ming Leu ◽  
Joontaek Park
Keyword(s):  
Experimental Data ◽  
Additive Manufacturing ◽  
Polylactic Acid ◽  
Extrusion Process ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Cross Sectional ◽  
Dependent Viscosity

A numerical model that incorporates temperature-dependent non-Newtonian viscosity was developed to simulate the extrusion process in extrusion-based additive manufacturing. Agreement with the experimental data was achieved by simulating a polylactic acid melt flow as a non-isothermal power law fluid using experimentally fitted parameters for polylactic acid. The model was used to investigate the temperature effect on the flow behavior, the cross-sectional area, and the uniformity of the extruded strand. OpenFOAM, an open source simulation tool based on the finite volume method, was used to perform the simulations. A computational module for solving the equations of non-isothermal multiphase flows was also developed to simulate the extrusion process under a small gap condition where the gap between the nozzle and the substrate surface is smaller than the nozzle diameter. Comparison of the strand shapes obtained from our model with isothermal Newtonian simulation, and experimental data confirms that our model improves the agreement with the experimental data. The result shows that the cross-sectional area of the extruded strand is sensitive to the temperature-dependent viscosity, especially in the small gap condition which has recently increased in popularity. Our numerical investigation was able to show nozzle temperature effects on the strand shape and surface topography which previously had been investigated and observed empirically only.

Creation and Maintenance of Cavities Under Horizontal Surfaces in Steady and Gust Flows

2009 ◽  
Vol 131 (11) ◽  
Author(s):  
R. E. A. Arndt ◽  
W. T. Hambleton ◽  
E. Kawakami ◽  
E. L. Amromin
Keyword(s):  
Experimental Data ◽  
Scaling Laws ◽  
Substantial Effect ◽  
Low Flow ◽  
Water Tunnel ◽  
Sectional Area ◽  
Cross Sectional ◽  
Air Supply ◽  
Wide Range ◽  
Flow Speeds

An experimental study of air supply to bottom cavities stabilized within a recess under a horizontal surface has been carried out in a specially designed water tunnel. The air supply necessary for creating and maintaining an air cavity in steady and gust flows has been determined over a wide range of speed. Flux-free ventilated cavitation at low flow speeds has been observed. Stable multiwave cavity forms at subcritical values of Froude number were also observed. It was found that the cross-sectional area of the air supply ducting has a substantial effect on the air demand. Air supply scaling laws were deduced and verified with the experimental data obtained.

scholarly journals The effect of geometry on the surface waves generated by vertical surface–piercing cylinders with a horizontal velocity

2017 ◽  
Vol 233 (1) ◽  
pp. 14-26 ◽  
Author(s):  
Alexander ST Conway ◽  
Dev Ranmuthugala ◽  
Jonathan R Binns ◽  
Martin Renilson
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Free Surface ◽  
Vertical Surface ◽  
Bluff Bodies ◽  
Sectional Area ◽  
Cross Sectional ◽  
Large Eddy Simulation Model ◽  
Eddy Simulation ◽  
Large Eddy

Bluff bodies advancing through a free surface at high Froude numbers create intricate flow patterns worth further investigation. An example of such flows includes a submarine operating near the free surface which generally will have one or more masts piercing the free surface. These have the potential to produce large wakes at the surface. This article describes the numerical analysis used to investigate possible design modifications to reduce the wake profile of a singular cylindrical mast piercing the free surface. The large eddy simulation model carried out in OpenFOAM computational fluid dynamics software was validated against experimental data obtained by the authors using tow tank experiments. The modifications included the use of a double mast system based on the cylindrical mast and truncated NACA0012 sections. All configurations were performed with a mast cross-sectional area corresponding to a typical submarine snorkel across speeds ranging from two to eight knots. The plume size and mast drag were recorded, and the results show that a 30% reduction in wake profile can be obtained using a double mast system at speeds around eight knots, while at the lower speeds the benefit is not as significant.

Noninvasive Inference of Airway Network Geometry From Broadband Lung Reflection Data

1978 ◽  
Vol 100 (3) ◽  
pp. 131-138 ◽  
Author(s):  
R. S. Sidell ◽  
J. J. Fredberg
Keyword(s):  
High Frequency ◽  
Bronchial Tree ◽  
Sectional Area ◽  
Inference Method ◽  
Cross Sectional ◽  
Response Data ◽  
Reflection Data ◽  
Network Geometry ◽  
Airway Opening ◽  
Airway Walls

An inference of the summed cross-sectional area of the airway network of the lung as a function of distance from the airway opening can be obtained noninvasively by inversion of high-frequency reflection response data with the Ware-Aki algorithm. This method is critically evaluated. The response of branching models of the complete tracheo-bronchial tree are simulated and inverted to produce an area versus distance inference. The models incorporate branching asymmetry, nonrigid walls, and a viscous gas. Direct comparison of the area inference with the anatomic area of the model indicates that the inference is markedly influenced by nonrigidity of the airway walls and branching asymmetry, and that the inference does not possess a simple anatomic correlate. Empirical uses of the inference method are not precluded.

Pelvic Canal Narrowing Caused by Triple Pelvic Osteotomy in the Dog

1994 ◽  
Vol 07 (03) ◽  
pp. 110-113 ◽  
Author(s):  
D. L. Holmberg ◽  
M. B. Hurtig ◽  
H. R. Sukhiani
Keyword(s):  
Postoperative Complications ◽  
Pelvic Osteotomy ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Canal Width ◽  
Operative Complications ◽  
Post Operative Complications

SummaryDuring a triple pelvic osteotomy, rotation of the free acetabular segment causes the pubic remnant on the acetabulum to rotate into the pelvic canal. The resulting narrowing may cause complications by impingement on the organs within the pelvic canal. Triple pelvic osteotomies were performed on ten cadaver pelves with pubic remnants equal to 0, 25, and 50% of the hemi-pubic length and angles of acetabular rotation of 20, 30, and 40 degrees. All combinations of pubic remnant lengths and angles of acetabular rotation caused a significant reduction in pelvic canal-width and cross-sectional area, when compared to the inact pelvis. Zero, 25, and 50% pubic remnants result in 15, 35, and 50% reductions in pelvic canal width respectively. Overrotation of the acetabulum should be avoided and the pubic remnant on the acetabular segment should be minimized to reduce postoperative complications due to pelvic canal narrowing.When performing triple pelvic osteotomies, the length of the pubic remnant on the acetabular segment and the angle of acetabular rotation both significantly narrow the pelvic canal. To reduce post-operative complications, due to narrowing of the pelvic canal, overrotation of the acetabulum should be avoided and the length of the pubic remnant should be minimized.

Effect of Varied Probe Length on the Resonant Frequency of a Circular Cross-Sectional Cavity

2005 ◽  
Vol 2 (2) ◽  
pp. 79
Author(s):  
Mohd Khairul Mohd Salleh ◽  
Mohamad Syukri Suhaili ◽  
Zuhani Ismail ◽  
Zaiki Awang
Keyword(s):  
Resonant Frequency ◽  
Cavity Resonator ◽  
Simple Design ◽  
Cross Sectional ◽  
Probe Length ◽  
Mode Wave ◽  
The One

A simple design of a metallic circular cross-sectional air-filled cavity is presented. Two probes of varied lengths are used to excite TE112-mode wave into the cavity to give a resonant frequency of 5.86 GHz. The experiments show that the resonant frequency of the cavity resonator decreases as the lengths of the probes are increased. The shortest probe in the range of study gives the closest resonant frequency to the one desired.

Diagnostics of metal samples using the results of experimental and theoretical study of positively charged microparticles formed upon sample destruction

2018 ◽  
Vol 84 (10) ◽  
pp. 23-28
Author(s):  
D. A. Golentsov ◽  
A. G. Gulin ◽  
Vladimir A. Likhter ◽  
K. E. Ulybyshev
Keyword(s):  
Experimental Data ◽  
Early Stage ◽  
Experimental Studies ◽  
Material Model ◽  
Total Charge ◽  
Cross Sectional ◽  
Practical Applications ◽  
Mechanical And Electrical Properties ◽  
Order Of Magnitude ◽  
Using Data

Destruction of bodies is accompanied by formation of both large and microscopic fragments. Numerous experiments on the rupture of different samples show that those fragments carry a positive electric charge. his phenomenon is of interest from the viewpoint of its potential application to contactless diagnostics of the early stage of destruction of the elements in various technical devices. However, the lack of understanding the nature of this phenomenon restricts the possibility of its practical applications. Experimental studies were carried out using an apparatus that allowed direct measurements of the total charge of the microparticles formed upon sample rupture and determination of their size and quantity. The results of rupture tests of duralumin and electrical steel showed that the size of microparticles is several tens of microns, the particle charge per particle is on the order of 10–14 C, and their amount can be estimated as the ratio of the cross-sectional area of the sample at the point of discontinuity to the square of the microparticle size. A model of charge formation on the microparticles is developed proceeding from the experimental data and current concept of the electron gas in metals. The model makes it possible to determine the charge of the microparticle using data on the particle size and mechanical and electrical properties of the material. Model estimates of the total charge of particles show order-of-magnitude agreement with the experimental data.

DETERMINATION OF THE FUNCTION OF THE ROD’S CROSS-SECTIONAL AREA USING VIBRATION EIGENFREQUENCIES

2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  
Keyword(s):  
Cross Sectional Area ◽  
Variable Cross ◽  
Sectional Area ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Method Error ◽  
Various Boundary Conditions ◽  
Elastic Fixation ◽  
Crosssectional Area

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.

Sign in / Sign up

Export Citation Format

Share Document