The purposes of this experiment are:
1. To determine the shape of the wake behind the cylinder.
2. To determine the water tunnel calibration.
Both of these objectives were accomplished by using LDA (Laser Doppler Anemometry). LDA is one of the main velocity measurement methods used in professional experimentation. Light beams are shot from a laser onto flowing water. In objective one, a cylinder was submersed in the water flow to determine how the velocity aft of the cylinder was disturbed. While the second objective used the LDA on flowing water with no disturbances.
This LDA system is an accurate system. However, every system has some kinks that are sources of error in the given results. Particle averaging bias is the first of these errors. This bias states that when the velocity is high the mean flow velocity well be larger than the actual value. This occurs because more particles’ velocities are being calculated than in a slower flow. Another source of error is called velocity gradient broadening. This error comes from the fact that two particles on different positions in the gradient will have different velocities but end up in the same measured volume. This will of course give a velocity variance where there should not be one. Lastly, there is an error called finite transit time broadening. This error occurs because the LDA system collects data using signal bursts, which will see fluctuations every burst even though the flow velocity is constant. Even though, these three errors and more are observed when using an LDA system, it is still one of the most accurate systems that is used to calculate flow velocity.
The first objective was examined by taking a series of data points with the laser configured to measure flow vel...
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... this experiment, the shape of the wake behind the cylinder was determined and the water tunnel was calibrated. The conclusions are listed below:
1. The horizontal flow velocities show that a wake is formed aft of the cylinder as expected.
2. The vertical flow velocities show that the flow is attempting to push the wake in, from both the top and bottom of the wake, and restore the water to its original state of steady flow.
3. If using this particular system and no flow velocities are being calculated by the system, move the laser slightly in any direction to obtain values.
4. Flow velocity versus the pump speed yields a linear graph with a R2 value of 0.99824 ± 0.00001.
5. If the pump speed is double, the flow velocity will also be doubled. Thus, ease of future experimentation.
6. The water tunnel is calibrated well and can be used as an accurate test bed.
Furthermore, using a graduated cylinder with markings below the 100 mL line would have allowed for more accurate measurements of the initial volume of air in the graduated cylinder.
Voynick and his partner came across an accumulation of water nearly two feet deep covering the rail trac...
On Tuesday in lab, we wanted to measure the velocity and acceleration of a ball rolling down an incline. To do this, we made our table have an incline by putting wood blocks under two legs of the table. We placed meter sticks on a table so we could determine the distance the ball traveled for a certain amount of time. We placed the ball at the 0cm mark on the meter stick and let go of the ball so it could roll down the table. To make our results more accurate, we videoed the ball rolling down the table with a stopwatch on our phone following the ball. We then went through the video and paused it at every 10cm and recorded the time it took for each 10cm interval from 0cm to 150cm. We did this experiment with 2cm, 4cm, and 6cm inclines to show
This object of the experiment was to demonstrate the average distance the ball traveled when shot from the spring gun. The test was used to show how the angle of elevation and initial velocity will affect where the ball is estimated to land. Using data collected on average distance found in part one of the experiment, you were then able to calculate time, when y=0 and yo= the distance from the spring gun to the floor, for part one using the equation Y=Y0+V0yT+1/2at2 (equation 1). Next, by using your average x you could calculate v0 using xavg = v0cosθt= v0 t (equation 2). Then, using the same v0 in part 2 you solve for t using equation 1 and then find xtheo using xtheo=v0cosθt (equation 3). Lastly, measure X, and find the average and then compare xtheo to xavg using | xavg-xtheo/xtheo | x 100 (equation 4).
chamber used as a control will be used to measure any changes due to air
Ocean currents are horizontal or vertical movement of both surface and deep water throughout the world’s oceans (Briney, n.d.). The primary generating forces are wind and differences in water density caused by variations in temperature and salinity. Currents generated by these forces are modified by factors such as the depth of the water, ocean floor topography and deflection by the rotation of the Earth. Horizontal currents are wind driven, fast moving and carries small amount of water; while, vertical currents are slow moving, density driven and carries large bodies of water. In this paper I will describe horizontal and vertical currents, their importance and some of the tools used to measure ocean currents.
A process flow diagram of the pump system is shown in Figure 1. The main components of the system are a centrifugal pump with a 4½-inch impeller, a 2-horsepower motor, a piping system with an effective length of about 285 feet, a rotameter for low liquid flow rates (0-2 gpm), a magnetic flow meter for high liquid flow rates (0-90 gpm), and a tank.
The purpose of this experiment was to make an object buoyant by adding a sufficient amount of extra volume to displace the water necessary.
There is also the potential of human error within this experiment for example finding the meniscus is important to get an accurate amount using the graduated pipettes and burettes. There is a possibility that at one point in the experiment a chemical was measured inaccurately affecting the results. To resolve this, the experiment should have been repeated three times.
...inty between 1.0% (0.1/10.00*100) and 2.13% in the measured volume and 0.1/4.70*100). We also used a digital thermometer that allowed us to read the temperature readings from five degrees celcius to eighty degrees celcius. Since the digital thermometer have an absolute accuracy of plus or minus one degree celcius, it gives a percent uncertainty between 0.125 % (0.1 / 5.00 * 100) and 0.2 % (0.1/ 80.0 * 100). One of the difficulties we faced during the lab is reading the inverted graduated cylinder. To account for the inverse meniscus, we subtracted 0.2 mL from all the volumetric measurements to account for that. Volumetric uncertainty is the most important in determining the accuracy of this experiment since we are constantly checking for the volume throughout the lab. It also is the factor that gives the highest percent uncertainty out of all the instruments used.
and into the jet unit which propels the boat to high velocities we would see
Fluid mechanics is a very wide field which is used in almost in every field. In this field the macroscopic motion of fluids is studied under the action of laws of classical mechanics. For scientist who tries to invent new things every time fluid mechanics gives them a good opportunity to make technical things. These can be used in aircraft designing’s, automobile engineering to rocket science. Advances in computer technology and algorithms have opened thi...
The foundations of fluid mechanics really crystallized in the 18th century. One of the more famous scientists, Daniel Bernoulli (1700–1782, Dutch-Swiss), point...
However, with a variation of liquids with various viscosities and the mixed phase of liquid and gas -, the content of the cylinder may not move with the cylinder at the same rate.
Da Rios studied the influence that the localised vorticity has on the behaviour of the vortex with a velocity proportional to it's local curvature. The set of basic assumptions that leads to the this law of motion is nowadays commonly referred to as the \LIA.