Design and Measurement of Pressure loss Junction Dividing into and Combining Six Branches

Abstract

Japan Foundation for Shipbuilding Advancement (Chairman R.Sasakawa) is planning to build a full scale experimental ship of superconducting electromagnetic propulsion. The thruster of the ship consists of six ducts placed on circumference of a circle and each of them is surrounded with a pair of superconducting coils and has a pair of electrodes inside. The thrust is generated by lorentz force due to interaction of the magnetic field and electric current in sea water going through the ducts. The present design of the ship puts the thruster inboard. The sea water therefore is led from an intake at the bow and flows into the thruster after divided into six branches at a junction. The sea water then increases in pressure in the thruster and flows into a duct at a combining junction to spout out from a nozzle at the stern. Development of junctions of low loss coefficient will provide high propulsive performance for the ship. Few reports however are found on the loss of junctions of multiple branches. The present paper deals with the tentative design of the junctions of six branches and measurement of pressure loss of the junctions with their models.