NVH Performance Optimization of Cylinder Head in Concept Stage

Cylinder head with good concept design provides possibility for excellent NVH performance of engine. In order to achieve this, NVH function of cylinder head should be taken into account at concept stage to make sure a good foundation for late stage of engineering. In this chapter, at concept stage of engine development, designs of three different cylinder heads such as global architecture, water jacket, bolt number, bolt position and ribs in different sections are evaluated and compared. In this way, good designs and weaknesses are separated and sorted out in views of NVH. Along with these good designs, one head design of these three is rebuild and recalculated by means of simulation. Results show good NVH improvement of modes and responses and eventually proved the validity of designs. By the research in this chapter, firstly, the NVH performance of production has been improved. Secondly, reasonable structure characteristics of cylinder head are obtained which could be a part of cylinder head design database in view of NVH. And one creditable simulation working flow, by use of mode analysis method and structural attenuation method, for improving cylinder head NVH performance in engine concept development stage is established as well.