This paper presents new developments on hot wire anemometer based panel noise contribution analysis. The used sensor allows the direct measurement of particle velocity. Some historical remarks are given and the latest developments of the technique are reported.
Four steps are required to determine the panel noise contribution of the interior of a vehicle and to visualize the results in 3D.
In a first step the probes are positioned on the interior surfaces and their x, y, z coordinates are measured. Based on these data a 3D geometry model is created. The geometry data are acquired using a specially designed 3D digitizer.
The second step is a measurement in a certain mode of operation. This step can be done in a laboratory but it is also possible to perform the measurement whilst driving the vehicle on the road. Stationary as well as non stationary running conditions like e.g. run ups are accessible and do not limit the applicability of the method.
The third step is the determination of the transfer paths from the panels to a certain listening position. This measurement is done reciprocally.
In a fourth and last step the transfer paths are linked with the operational data gathered in step two. The results are then visualized using the 3D geometry model.
This paper describes the measurement of a conventional car with a resolution of 180 panels. Since an array of 45 probes was used step 2 and step 3 had to be repeated 4 times.
The complete measurement typically takes approximately 3 days.