ME 31000: Fluid Mechanics LabExperimental Report

Course Number and Name:Me 31000-Fluid Mechanics

Semester and Year:Fall 2014

Group Number:Group 1

Name of Lab Instructor:Mohit Suri

Lab Section and Meeting Time:24661-R 7:30pm

Experiment Number:Exp 7

Title of Experiment:Pipe Flow from an Open Tank

Date of Experiment Performed:10/30/2014

Instructor Comments:

Date of Report Submitted:11/06/2014

Names of Group Members:Fielden, Kristina

Phoraris, George

Mansilla, Filipecki Fernando

Cooper, Evan

Summitt, Zakery

Grade:

ME 310 Lab reportGroup 1 Exp 7

17

ABSTRACTCooper, Evan

Objectives

The objectives of this experiment are twofold: 1. Compare the experimental and theoretical efflux times of water falling through a pipe in a given head range; and 2. Determine the effects of pipe length and diameter on the efflux times, given that one of these factors is constant. These objectives will help further an understanding of fluid mechanics as it relates to efflux times.

Type of Experiment

The experiment to be run uses a tank apparatus attached to a pipe fitting. The tank is to be filled up with water, and a pipe will be attached. At a range of head heights, the efflux time will be recorded by the group. The variables in each experiment will either be the pipe length or the pipe diameter.

Major Results

According to the data, the experimental and theoretical efflux times are incredibly similar to each other. The efflux times decreased as the pipe diameter was increased while length was held constant, and vice versa.

Conclusion

The experiment itself showed that the theoretical equations used to calculate the theoretical efflux time is valid. The fact that efflux times decrease as pipe diameter increases is a common sense conclusion, while the increasing length result can be explained by the laminar flow model.

INTROCooper, Evan

Goals

The goals of this experiment are to determine the effects of pipe length and diameter on the efflux times, as well as compare the experimental and theoretical efflux times of water falling through a pipe in a given head range. These objectives will help further an understanding of fluid mechanics as it relates to efflux times and overall pipe flow problems.

Real World Application

One of the major uses of pipe flow and efflux times is the building of oil pipelines. The pipelines, such as the Keystone XL pipeline currently under debate, need to be able to supply the proper amount of crude from the drilling sites to the oil refinery stations. If the calculations for efflux time are not correct, then either too much or too little oil will travel through the pipes, leading to problems for the refineries.

THEORY AND EXPERIMENTAL METHODSFielden, Kristina; Phoraris, George

Description of Apparatus

An open tank has a diameter of 5.4375 inches and a depth of 12 inches. The tank has a small hole centered at the bottom that allows for each pipe to screw on tightly. Pipes will vary by length and diameters that allow water to flow out of the tank. There is a scale attached to the tank that allows accurate measurements to calculate rate of flow in increments of one tenth of a foot. A pan will be set below the pipe to collect all the water fallen.

Theory of Pipe Dimensions

Table 1Pipe 1Pipe 2Pipe 3

Diameter0.12 in.3/16 in.5/16 in.

Length24 in.24 in.24 in.

Table 2Pipe 4Pipe 5Pipe 6

Diameter3/16 in.3/16 in.3/16 in.

Length3.915 in.6 in.24 in.

Table 1 allows the group to make the comparison of pipes with the same length but with different diameters. With this information, flow rate can be determined. Knowing the flow rate of each pipe with the same length will help determine if the change in diameter makes a difference in the flow rate. Along with table 2, this will allow the group to compare the flow rate of pipes with the same diameter with varied lengths. Knowing the flow rate of each pipe with the same diameter will help determine if the change in length makes a difference in the flow rate.

Note that pipe 2 and 6 have the same dimensions.

Efflux time is the time taken for the water to drain between certain intervals. For the most accurate results, this experiment will take the average of three timers for each reading. Having three different timers allows a minimal of human error for this procedure.

Experimental Procedure

First fill the tank full with water Note that the water will begin draining once the water hits the bottom of the tank. It is important for the timer to be ready or plug the end of the pipe to stop the water from flowing. Have a timer ready As stated before, there will be an average of three timers used for the calculations in this experiment. The time will be measured in intervals of one tenth of a foot. 8.5-7.5 in. 6.5-5.5 in. 3.5-2.5 in Once the water level reaches the measurement on the scale, the time will start or stop. Once you have all three average times, let the water drain completely out and proceed onto the next pipe. Make sure to screw in the pipe tight and secure. Water leakage will slightly through off the calculations for the efflux time and flow rate.

Assumptions: Steady flow Incompressible flow Pipes with uniform diameter Fully developed pipe flow

Energy Equation:

4.1

4.2

In 4.1 and 4.2 H+L is the total head, H- liquid depth in the tank, L-length of vertical pipe, g- gravitational acceleration (g=31.174 ft/s^2), V is average flow velocity in the pipe, K is the ID and f is the friction factor

Values of f for tests using water at room temperature, smooth pipes with no bends and average head H of .6 ft are seen in Table 3

Evaluating the Reynolds number for each pipe and determining f using the Moody diagramand compare it to the selected one using the smooth pipe curveParameters , f and K are dependent on the Re.

4.3

Parameter v- kinematic viscosity of water, Re>2300 laminar in a pipe, Re