Jaguar Cars is a subsidiary of Ford Motor Co. that produces luxury motor vehicles. A minimum 80 percent of peak torque is available between 1,400 and 6,400 rpm for quick acceleration across an unusually wide range of speeds. The AJ-V8 is also the lightest engine in its class, at 441 pounds. Engineers working on new engine variants were charged with the task of significantly reducing combustion emissions and improving fuel economy. One of the primary means by which they set out to accomplish this task was to improve the flow characteristics of the inlet port and chamber.
Turbulence tends to increase with engine speed.
Designers need to maintain turbulence at high enough levels at low speeds to provide a stable idle and good acceleration, yet avoid excessive turbulence at high speeds that will be experienced as noise by the occupants of the vehicle. The traditional method of resolving these tradeoffs in the design of the inlet port and chamber is to build a prototype of conceptual port designs and test them on a steady state rig. Through an iterative approach, the port is tuned to provide the required motion and flow characteristics. One problem with this approach is that it takes about a month to build and test a prototype of the inlet port and chamber. The cost and time involved in building the port places a limitation on the number of different designs that can be evaluated.