The Design And Optimization Of Cooling System For The Water-Jet Propulsion Diesel Engine

In this paper, the improved design of the cooling system and optimization of theintercooler’s performance are investigated and analyzed while the vehicle diesel engine ismodified for the marine propulsion.Because of working without wind ward airflow while the vehicle diesel engine isinstalled in the cabin, the cooling system of the vehicle diesel engine need to be changedfrom "air-cooled" to "water-cooled"(remove the fan、radiator and other equipment, installthe sea water pump、fresh water cooler、oil cooler and intercooler). The research object is adirect injection boat diesel engine cooling system, according to the basic parameters and itsworking condition of the diesel engine, to design the intercooler and fresh water cooler,verify the cooling system through the test, and numerical simulations are performed toinvestigate the flow and heat transfer coupling characteristics of the intercooler, some meansare studied to strengthen the heat transfer performance of the intercooler. The main contentsinclude the following aspects:1. The boat diesel engine cooling system are analyzed, according to the relatedparameters of the diesel engine and its working condition, the intercooler and fresh watercooler are designed which are matching the diesel engine, the thermodynamic calculationand check calculation are conducted for the intercooler and fresh water cooler, while thedetailed structure design are conducted.2. The diesel engine cooling system test is conducted to verify its reliability. Throughthe test, it is known that the design calculation method of the intercooler and the fresh watercooler are reasonable, the diesel engine cooling system can satisfy the working requirementsof the diesel engine.3. The numerical simulations are performed to investigate the flow and heat transfercoupling characteristics of the intercooler with the vortex generators. The results show thatthe thermal capacity and flow loss are increasing while the vortex generators are setting up,but the proportion of the heat transfer enhancement is obviously higher than the increasingof the resistance, so the comprehensive performance of the intercooler is improved.4. The traditional vortex generator is improved and a new type of circular-arc deltawing vortex generator is developed, the numerical simulation is performed to investigate it.The results show that the flow resistance of circular-arc delta winglets is obviously less thanthe traditional vortex generator, it is suggested that the circular-arc delta winglet is a kind ofhigh efficiency and low resistance structure form.