Design of an Experimental Setup to Carry Out Flow Measurements to Create a Database for Airflow Characteristics for Low Pressure Ducting in Boeing Commercial Airplanes
Air Flow Design Group:
Sponsor Company:
Faculty Coach:
Ali Abdulrahim
Ritik Chojar
Kevin Frederick
Jordan Gray
Ian Marcus
Boeing Commercial Airplanes
Dr. Savas Yavuzkurt
The Boeing Company is one of the leaders in the development of planes and aerodynamic studies. They are the largest suppliers of commercial jetliners and military aircraft combined. Boeing also manufactures missiles, electronic and defense systems, rotocrafts, satellites, and launch vehicles. Boeing also works with NASA by operating the International Space Station. [1]
Boeing is now looking to the Penn State Mechanical Engineering Department for help in designing an experimental configuration in order to create a database for air flow measurements that are not well recorded in engineering manuals. These measurements are important so that theoretical calculations can be validated and to ensure the safe operation of low pressure systems on Boeing Commercial Airplanes.
The database that Boeing would like to create includes pressure drops and velocity measurements for irregular geometries of low pressure ducting. These measurements should be taken at a variety of Reynolds numbers, specifically in the range between 4,000 and 20,000.
The core of the problem is to create a permanent system that can be adjusted to test various ducting systems on Boeing Commercial Airplanes. This is to be done by having a blower push air through piping, including an orifice flow meter to ensure the Reynolds number. This piping then matches to a ducting assembly to be tested, and a great length of pipe is at the end of the permanent part to ensure fully developed flow. See 'Figure a' below for a schematic of the permanent system with the flexible ducting as the piece being tested.
Figure a: Schematic of Permanent System with Flexible Ducting
Once the assembly to be tested is attached to the permanent part, velocity and pressure profiles will be taken at various points along the tested assembly. A full velocity profile will be taken at four points, including the axially and radial components. The pressure will be taken every five diameters along to pipe to see how it drops along the length.
This data will be compiled in a database. Necessary graphs and tables will be created, and the information will then be sent to Boeing as part of our agreed upon deliverables. This data will then be used to ensure proper operation of the low pressure systems on Boeing Commercial Airplanes.
The results obtained from experimentation follow logically with what would be expected to happen. The pressure drop in the straight piping dropped off linearly with a very shallow slope. This is expected because the only pressure drop would be from the friction of the pipe walls. There was also a sharp pressure drop right at the tested ducting. This is an expected loss because of the sudden change in direction of the flow. 'Figure b' below is plot of the gage pressure along the length of the 90 degree bend of flexible ducting.
Figure b: Plot of Gage Pressure Along Length of 90 Degree Flexible Ducting System
The velocity profile of the flow before and after the tested ducting were also what was to expected. Before the elbow bend, the velocity profile was parabolic because the air flow was fully developed. After the tested ducting the velocity profile was turbulent and erratic. 'Figure c' is a plot of a sample velocity profile after a tested ducting.
Figure c: Horizontal Velocity Profile After Hard Bend, Re=20,000
