Application of PIV to characterise the Flow- Phenomena of a Heavy-Duty Cylinder Head on a Stationary Flow-Bench E. Doosje 1 , R.J.M. Bastiaans, R.S.G. Baert Eindhoven University of Technology Abstract With modern heavy-duty diesel engines the design of the inlet ports in the cylinder head is such that some degree of swirling motion is induced in the engine cylin- ders during intake. This swirling motion is mostly characterized using a stationary flow bench. In such a flow bench, a dummy cylinder is used instead of the cylin- der in the engine. In this situation there is no moving piston, the air can flow out of the open end of the dummy cylinder. To measure the intensity of the swirling motion a swirl-torquemeter is used. This swirl-torquemeter is a flow rectifier, which is placed in the dummy cylinder. The restraining torque on the flow rectifier is a measure of the momentum in the flow. Simulations of the flow in the cylinder indicate that the flow is influenced by the flow-rectifier in such a way that the measured values can be questioned. One of the objectives in this research is to find out if this influence exists. To do this, the velocity field in the cylinder is measured using Particle Image Veloci- metry (PIV). From the velocity measurements, the swirl was calculated and compared to the swirl measured using a swirl-torquemeter. The validity of the assumptions made when using a swirl-torquemeter was evaluated from the velocity fields. Last, tur- bulence characteristics were determined and a spectrum was made. 1 Introduction In diesel engines, the motion of the charge is used to promote the mixing of fuel and air in the combustion chamber at the moment the fuel is injected ([3],[4]). In heavy-duty engines (e.g. truck applications or stationary power generation) a ro- tating air motion is used. This air motion is called swirl. The axis of rotation is parallel to the cylinder axis, but does not necessarily coincide with it. To measure the rotational speed of this air motion different methods are applied. In the indus- try so called swirl-torquemeters are commonly used. These measurements are per- formed on a flow-bench rather than in a running engine. On such a flow-bench the cylinder head to be measured is placed in normal or upside-down orientation; a 1 Corresponding author, email: e.doosje@tue.nl