A 4 meter tall reactor vessel contains a bubbly solution of

A 4 meter tall reactor vessel contains a bubbly solution of ethyl alcohol and hydrogen gas at moderate pressure. The small gas bubbles slowly expand as the bubbles rise toward the top of the reactor. Assume the fraction of the volume occupied by the bubbles varies linearly from 10% at the bottom to 50% at the top. The hydrogen bubbles are small and move slowly enough to be considered static. The hydrogen gas density is negligible. Surface tension is negligible. The process is not isothermal. Given: At the top location (0): p_0 = 50 kPa, gauge. Find the gauge pressure at the center & the bottom, p_1 = & p_2 = (kPa) Plot the pressure variation vs elevation (p as a function of z): p(z) vs z A 10 meter deep aquarium is filled with seawater. Square (2m Times 2m) windows are located at several viewing levels. For each window, determine the magnitude of the pressure force, F_P, (kN), and the distance the center of pressure is located below the window center, Delta z, (m).

Solution

gauge pressure is the additional pressure in the system relative to the atmospheric pressue.it is a convinient pressure measurement for the most practical applications

gauge pressure is the absolute pressure minus the atmospheric pressure. Most pressure measuring equipment give the pressure of a system in terms of gauge pressure as opposed to absolute pressure

For most working fluids where a fluid exists in a closed system, gauge pressure measurement prevails. Pressure instruments connected to the system will indicate pressures relative to the current atmospheric pressure. The situation changes when extreme vacuum pressures are measured; absolute pressures are typically used instead.