Bihrle Applied Research LAMP Facility

The LAMP facility consists of an open circuit, 78' high, low-speed vertical wind tunnel having a circular cross section. The tunnel is located within a building that also contains offices and test support facilities and is designed for handling and processing classified material. The wind tunnel uses a six-to-one contraction ratio inlet that was designed using finite element analysis to provide a uniform test section velocity profile.

Above the inlet, a ten-foot high constant ten-foot diameter circular cross-section test area is used for all static, rotational, forced oscillation, pressure, and flow visualization tests. Within this test section, the velocity can be set at any desired speed, up to a maximum of 120 ft/sec. The test section is accessed through a set of doors and viewed through a large Plexiglas window located above the tunnel control console.

Model installation and configuration modifications are conveniently performed in the area outside the tunnel test section since the entire test rig, including the model, can be quickly moved in an out of the tunnel on a motorized traveling beam.

 

The test rig that operates in this test section was designed to provide maximum operational flexibility. A double C-sector sting support system provides the capability for continuous sideslip and angle-of-attack sweeps of ± 30 degrees and 0 to +90 degrees, respectively. The inner, i.e., angle-of-attack sector, has sting attachment points at 0 degrees, 45 degrees, and 90 degrees to allow maximum model mounting possibilities. With these sting mounts, in conjunction with the large angle C sector, a full ±180 degrees angle-of-attack range is easily obtained. By using alternate mountings, a ±90 sideslip range is also possible.

View Rotary Movie [MPG 920K]

Two oscillatory stings, capable of sinusoidal motions at selected amplitudes and frequencies, also attach to the test rig to measure the body-axis damping characteristics about the pitch, yaw, and roll axis throughout the angle of attack and sideslip ranges, as well as hysteresis at wing stall.

View Roll Oscillation Movie [MPG 921K]

While all these test capabilities are obviously available with the test rig fixed, further capabilities are achieved because of the rig's ability to rotate up to 150 revolutions per minute. The same angle-of-attack and sideslip ranges are available during steady-state rotation tests. In addition, forced oscillation tests can be performed with the rig rotating. Consequently, the dynamic characteristics of a configuration can be determined in a steady rotating environment.

View Combined Motion Movie [MPG 920K]

In addition to the force measurement capabilities, the test rig's design conveniently lends itself to other testing disciplines. With the large number of available slip rings, pressure measurements can be performed in rotational flow. The utilization of these techniques, in conjunction with force and moment airplane component testing, provides unprecedented insight into a configuration's aerodynamic characteristics.

While most tests involve force measurements on standard unpowered wind tunnel models, Bihrle has developed test techniques and programs for unorthodox models as well. These include steady-state rotational tests of propeller/rotor powered models as well as models featuring forebody blowing for vortex control. Such techniques provide the capability to measure force and pressure on such devices as rotating helicopter rotors, wind turbine blades, or during weapons separation studies.

Tunnel operation, data acquisition, reduction and plotting are completely automated in this facility. Typical test report documentation provided by Bihrle includes plotted data with recommendations and conclusions on the tested configurations. Electronic data sets, video, and photographs are also included where appropriate.