Facilities and Specifications :
GLM Wind Tunnel
- Test Section: 7.75' High, 11.04' Wide with corner fillets. Test section area is 85.04 sq. ft.
- Speed Range: 2 m.p.h. to 230 m.p.h (Mach Number 0 to 0.3).
- Turbulence: Sphere test turbulence factor is 1.05. Hot wire measured intensity is 0.21%.
- External Balance: Six component yoke type balance. Normal mounting of test articles is from below floor. Balance extension allows mounting of test articles from above the test section roof. This also allows "2D" airfoil tests with the test wing extending from floor to ceiling with attachments to the balance at both the top and bottom.
- Model Control: Multi-axis control under manual remote or computer program command
- Test Section Insert: Horizontal endplate type to perform two-dimensional flow studies within the main tunnel. Use of balance extension described above is the preferred method of doing a 2D test.
- Floor Boundary Layer Control System: Ground floor Boundary Layer (GFBL) Suction system provides floor boundary layer with displacement thickness of ~1/8" at center of test section for automotive and other test applications.
- Shop: Complete model shop for fabrication of models and fixtures, including CNC machining and stereolithography rapid prototyping.
- In-House Design Capability: Mechanical and structural design using Solidworks, Rhino, and AutoCAD drafting and solid-modeling programs for models and fixtures.
- Data Acquisition System: Hewlett Packard 743 VXI bus workstation. User customized data acquisition system designs and sophisticated graphical user interfaces can be easily created using icon-driven software VEETEST.
- Post-Processing: MATLAB based post-processing software allows on-line corrected data to be displayed on customer's CRT in tabular and graphical format immediately following completion of each data run.
- Flow Visualization: Smoke systems, fluorescent oil, tufts, and computer based presentation.
- Flow Field Surveys: Extensive capabilities for measuring, computing, and displaying flow field properties such as velocity components, vorticity, and other derived variables, using a variety of probes such as 7-hole, and hot wire, including a wake survey rig with six 7-hole probes.
- Pressure Measurements: PSI 8400 system provides miniature modules which can be mounted in models. Other transducers are available for other pressure measurements. Unsteady pressure measurements using high speed pressure transducers.
- Hot Wire Measurements: TSI hot wire data acquisition system.
- Test Section Video System: Digital video (2 Prosilica GigE digital color cameras mounted inside test section, Sony SteadyShot on external tripod for multiple video angles, VHS and direct DVD recording). Adobe Premiere Pro for custom video editing. Digital cameras for most still applications.
- Computer Network: Dell workstations and servers on Ethernet LAN. Local intranet accomodates data services within the GLMWT and provides a secure connection while access to the University of Maryland campus network affords an outlet to the external world as needed.
Computational Fluid Dynamics (CFD) Capability
- The highly qualified staff focuses on providing design support, including computational fluid dynamics (CFD) and experimental fluid dynamics (EFD) evaluations and parametric studies for a broad array of vehicles and other devices. Staff has expertise and experience in automotive, aviation, sports, and marine applications. Student research projects are also supported.
- The dynamic testing system provides information from which aerodynamic damping about each of the 3 axes can be measured over a range of conditions. Specially designed mounting fisctures allow asingle degree of freedom rotation about the pitch, yas, and roll axes. The moments of inertia are measured about each of the axes. In some cases the model is free to rotate with the estraint coming only from an offset center of gravity and the aerodynamic forces. In other cases mechanical spring restrains are applied to provide useful equilibrium points about wich the dynamic properties of perturbations are measured.