Preparing to Collect Data
By Mina Cappuccio
July 21, 1999
As the head researcher on the project, I choose the measurements that that will be taken during the test. So six weeks ago I submitted to the Test Manager, Jules Gustie, the data requirements and he has assigned the mechanics and engineers to accomplish this work.
The model is just about to come out of the prep room. While it was in the prep room the balance was installed on the model and checkloaded. The model was assembled and the model was plumbed to the Electronic Scanned Pressures (ESP).
During this test, we will be measuring the air pressure on the surface of the model at over 300 locations on the wings. On one side of the plane the pressures are being measured on the top of the wing and on the other side of the plane we are measuring the pressures underneath the wing. At each of the locations where pressure is measured there is a pinprick-sized hole which is attached to a tiny stainless steel tube which is attached to the ESP modules. There are five five modules, each with 64 transducers, in the model. The ESP system takes the air pressure measurement as a voltage. The voltage is sent to the data acquisition system and converted to an air pressure measurement.
Some of the data I have asked for is visual data, both video and digital still images. To collect this data we have painted the model. We do this before putting the model in the tunnel so we don't spill any paint in the tunnel.
The data acquisition system has been customized for this test. This means that the constants for this particular model have been put into the computer program. . Calibration constants for converting analog and digital signals have also been put in the program. These signals come from instruments like the balance, ESP modules, and motors that drive parts remotely like the canard.
Today, the model will be moved from the model prep room to the tunnel. This week will be spent making sure all the instruments are connected to the data acquisition system and are working properly. The model will also be put in its final configuration for when we are ready to run.