A computational fluid dynamic model that simulates the developmental process of the human brain is proposed. The bones of the skull become increasingly larger over the neck and also soup-like fluid for generating brain cells enters the skull from the body. This process is essentially similar to the intake process of an internal combustion engine, because the volume of engine cylinder, which increases according to the descent of the piston, geometrically corresponds to the development of the skull and also because the human neck resembles the intake port of the engine. A higher-order numerical computation of the Navier-Stokes equation at very low engine speed reveals the similarity between the convexoconcave forms inside the brain and the flow structure in the internal combustion engine. We will show that the present computation also simulates the nose and the eyeballs.