|M.Sc Student||Oren Koren|
|Subject||Water Tank Testing of a Laboratory Two-Phase Marine Ramjet|
|Department||Department of Aerospace Engineering||Supervisor||Professor Emeritus Gany Alon|
deals with investigation and characterization
of a two-phase marine ramjet engine. The operating principle of this marine
engine is similar to that of the aeronautical ramjet engine, using water
instead of air as the main working fluid. Energy is added via introduction of
compressed air in a mixing chamber instead of a combustion process in a combustion
chamber. Water enters the inlet due to vessel motion, and its pressure is
increased while flowing through the diffuser; then it is mixed with compressed
air at the mixing chamber, creating a two-phase jet, which generates thrust.
A propulsion system exploiting this principle can be a promising alternative to conventional water propulsion systems based on propellers or pumps, especially in the high cruise speed range over 30 knots. The marine ramjet has no moving parts in contact with the water, and the power is transmitted to the water pneumatically. This gives the propulsion unit a long life span and simple maintenance.
The objectives of this research were :
The test rig consisted of a
10-meter diameter water tank, connected to air supply, control and data
acquisition systems. Marine ramjet engine models of two different geometries were
Performance data were acquired experimentally, running the test system at different speeds (between 5 and 13 m/s, approximately 10 to 26 knots) and different air flow rates.
Comparison between the experimental results and theoretical predictions revealed good qualitative and fair quantitative agreement.