INTER AMERlCAN UNIVERSITY OF PUERTO RICO
BAYAMÓN CAMPUS
DEPARTMENT OF MECHANICAL ENGINEERlNG
Fluid Mechanics Laboratory: MECN 3110
Experiment No.2
A. Title:
Center of Pressure
B. Equipment:
Center of Pressure Apparatus, and, Thermometer
C. Main Goal:
To familiarize the student with the pressure center apparatus to understand
the concept of hydrostatic pressure distribution and how to calculate the pressure center
of submerged surfaces.
D. Prior Requirements:
1. Understand how the hydraulic bench operates as well as which are its parts.
2. Read and understand the notes given by the Instructor.
E. Procedure:
1. Set up the equipment as previously described in Section 1.2 of the Annex-Lab2, and
affix the weight hanger to the hanger support located on the top left of the hopper.
The apparatus will now require trimming in order to bring the submerged plane to
the vertical (i.e. 0° position). This is achieved by gently pouring water into the trim
tank until the desired position is achieved. The horizontal line on the tank assembly
should be read against 'the zero line on the back scale.
2. Add a 20 g weight to the weight hanger. Pour water, with dye added if necessary,
into the quadrant tank until a 0° balance is restored. Note the weight and the height
reading of the water (h). Repeat the procedure for the full range of weights.
3. Empty both tanks of water. Again, with the weight hanger alone in position, trim the
assembly by gently adding water to the trim tank until a 30° balance is achieved.
Add a 20 g weight, restore balance to 30° point and record values for h for the full
range of weights.
4. Readings may be tabulated in the form outlined in Table 1 and the results calculated
in line with the theory given in Section 2 of the Annex-Lab2
M
ω
(gm)
𝑊𝑥9.81𝑥𝑅3
103
(𝑁𝑚)
h
(mm)
h
(m)
h3
(m3)
𝑀+
𝜔𝐵𝑅22 ℎ
2
(Nm)
Figures 1 and 2 show the general form of the graphs expected from this experiment.
Figure 1 Graph showing plane fully submerged
θo
Figure 2 Graph showing plane partially submerged