Mech Eng Yr1 Fluid Dynamics Lab Report
PRAXIS Semester 1
Fluid Mechanics Lab Report
Contents Objective 3 Theory 3 Experimental Method 4 Equipment needed for this experiment 4 Procedure 4 Results 5 Discussion of Results 6 Sources of errors 8 Conclusions 8 References 8
Objective
The objective of performing this experiment is to measure the hydrostatic force on a partially submerged vertical surface and to compare the force found in the experiment to the theoretical equivalents.
Theory
A submerged body will experience a hydrostatic force due to the weight of the fluid above it as indicated in the figure below:
The magnitude of the resultant force (Fh) is the product of the pressure at the centroid (ρgy) and the surface area (A). The line of action of this force (Yp) is at a distance (Yc) below the centroid (y). For a vertical surface, it can be shown that: y=h2 Yc=h6 Yp=y+Yc
∴Yp=2h3
Experimental Method
Equipment needed for this experiment
As indicated in the diagram below a partially submerged dam wall is connected to a crossbeam that pivots on a fulcrum above the water tank. The crossbeam also extends at a distance perpendicular to the dam surface. This lever arm can be loaded with different weights: thus creating an effective balance with the hydrostatic load. The tank has an attached device used to measure the amount of water in the tank in millimeters (mm). A spirit-level on the lever arm indicates when the lever is balanced horizontally.
Free body diagram of apparatus:
Procedure 1. Assemble test device. 2. Adjust the weight balance to level arm by means of the adjustable end weight. 3. Add a weight of 20g to the weight tray and fill tank with water until the crossbeam is balanced. Note result. 4. Increase weight in the tray by 20g increments and note the corresponding water level required to re-balance the crossbeam. Repeat until 200g of weight has been used.
Results
Mass (kg) | Weight (N) | Water height (m) |
Fluid Mechanics Lab Report
Contents Objective 3 Theory 3 Experimental Method 4 Equipment needed for this experiment 4 Procedure 4 Results 5 Discussion of Results 6 Sources of errors 8 Conclusions 8 References 8
Objective
The objective of performing this experiment is to measure the hydrostatic force on a partially submerged vertical surface and to compare the force found in the experiment to the theoretical equivalents.
Theory
A submerged body will experience a hydrostatic force due to the weight of the fluid above it as indicated in the figure below:
The magnitude of the resultant force (Fh) is the product of the pressure at the centroid (ρgy) and the surface area (A). The line of action of this force (Yp) is at a distance (Yc) below the centroid (y). For a vertical surface, it can be shown that: y=h2 Yc=h6 Yp=y+Yc
∴Yp=2h3
Experimental Method
Equipment needed for this experiment
As indicated in the diagram below a partially submerged dam wall is connected to a crossbeam that pivots on a fulcrum above the water tank. The crossbeam also extends at a distance perpendicular to the dam surface. This lever arm can be loaded with different weights: thus creating an effective balance with the hydrostatic load. The tank has an attached device used to measure the amount of water in the tank in millimeters (mm). A spirit-level on the lever arm indicates when the lever is balanced horizontally.
Free body diagram of apparatus:
Procedure 1. Assemble test device. 2. Adjust the weight balance to level arm by means of the adjustable end weight. 3. Add a weight of 20g to the weight tray and fill tank with water until the crossbeam is balanced. Note result. 4. Increase weight in the tray by 20g increments and note the corresponding water level required to re-balance the crossbeam. Repeat until 200g of weight has been used.
Results
Mass (kg) | Weight (N) | Water height (m) |
References: “STEPS FOR CALCULATING THE HYDROSTATIC FORCE AND THE CENTER OF PRESSURE ON SUBMERGED SURFACES.pdf” http://www.engr.sjsu.edu/nikos/courses/me111/pdf/steps.pdf