Vandresen, M., Cazangi, H., Tomasi, B., and Fernandes, R., "Development of an Academic Swirlmeter System for Measuring Air Flow in Automotive Engine Heads," SAE Technical Paper 2015-36-0283, 2015, doi:10.4271/2015-36-0283.
Conventional airflow benches do not measure the swirl airflow effect, being restricted to indicate the flow for a given test pressure. This effect directly affects the volumetric efficiency of the engine and, therefore, the performance and fuel consumption of the vehicles. The behavior of swirl in the intake airflow improves the filling capacity of the combustion chamber, homogenizes the air fuel mixture and improves the fuel combustion efficiency, enabling the engine to deliver more power in the same cycle. This paper describes the development of a swirl measurement system to be adapted to conventional flow benches offered on the market, which can be also applied in other tests where the flow swirl effect is important. The state of the art is discussed in depth presenting mathematical models of the problem, parameters involved in the design of the swirl measurement system, mechanical systems modeled in CAD, and the electronic circuit diagrammatically represented and finally, the prototype built and calibration tests performed with existing head. The tests were carried out with engine heads and the results are discussed in order to understand the behavior of the swirl measurement and its impacts over the airflow.