Study On Cooling Water Jacket Flowing Non-uniformity Of V-type Six-cylinder

Cooling system is an important part of diesel engine.Reasonable cooling system can ensure effective work of diesel engine.However,cylinders’non-uniformity leads to the different operating conditions and reduces practical effect of the cooling system.The three dimensional model of cooling water jacket is built by Solid Works,including waterway of cylinder head,cylinder head,cylinder jacket,radiator and back pipe.The grid models are built by Meshing software.The fluid field simulation calculation of different work conditions are conducted by Fluent software.The results show that,with the import and export pressure of V-type six-cylinder diesel engine decreasing,the flow rate reduces.The overall pressure on the left side 1-3 cylinder is higher than the right side 4-6 cylinder.The inlet pressure of each cylinder head,from the inlet to away inlet,reduces.The outlet pressure of each cylinder head from the outlet to away outlet increases.The non-uniformity of left 1-3 cylinder stabilized at 29%.The non-uniformity of right 4-6 cylinder stabilized at 23%.1-6cylinder overall non-uniformity stabilized at 35%.The structural optimizations of the cooling water jacket are designed.When the up chamber-down chamber of both 1^st and 4^th cylinder water jacket connects,the overall field changes little.1^st and 4^th chlinder up chamber-down chamber widens and more coolant flows.Non-uniformity does not change much.When both of 1-2 cylinder water jacket and 4-5cylinder water jacket connect,the overall flow field changes.Velocity of both 1-2 cylinder and 4-5 cylinder connection hole is significantly reduced.The down chamber of 1^st and 4^thcylinder has a coolant flow.Non-nuniformity doesn’t change much.When the radiator is set to wall as others,radiator pressure at both ends changes obviously.The difference between left and right cooling water jacket becomes smaller.But non-uniformity of left side and right side change little.When import and export of V-type six-cylinder cooling water jacket swap position.The overall flow field changes obviously.The coolant flow changes from bottom-top to top-bottom and the pressure field and flow rate also change correspondingly.The non-uniformity of both sides is greatly improved.When the outlet of V-type six-cylinder cooling system is move to the other end,both non-uniformities of both sides are less than 20%.1-6 cylinder’s non-uniformity is 20%.The final optimization of V-type six-cylinder diesel engine cooling system is obtained.After the optimization,the non-uniformity of 1-3 cylinder is reduced to 9%,which is the same to the 4-6 cylinder’s non-uniformity.The non-uniformity of 1-6 cylinder is reduced to12%.The non-uniformity of both sides of cooling water chamber are 9%.Both sides have same cooling performance.