Flow Diagnostics

MetroLaser has developed a high frequency, digital photonic, two-dimensional wavefront sensor system for flow diagnostics and aero optics. The system employs a 532 nm diode pumped solid state laser to produce quantitative, fully reduced phase maps at virtually real time acquisition rates to evaluate flows in wind tunnel facilities. This is achieved with MetroLaser’s patented instantaneous electronic phase shifting interferometry methods. Because measurements are instantaneous and not compared to a stored reference data point, the instrument is not vulnerable to vibrations and other environmental effects found in test facilities. Software required for applying electronic interferometry in typical wind tunnel testing is included, as well as software required in other applications; specifically, the software that is needed to allow large amounts of data to be acquired in a short time, stored in a buffer, and retrieved later for analysis, and the software that allows the comparison of a flow field with itself at different times.

Digital Optical Flow Diagnostics System Using Fiber Optics
Digital Optical Flow Diagnostics System Using Fiber Optics

A schematic of the system in a Scram jet facility is shown above. A convenient and powerful feature of this system is that the reference beam may be transmitted to the optics head via fiber optics.

Features Include:

  • Instantaneous quantitative wavefront diagnostics
  • Electronic recording on CCD arrays
  • Double recordings possible with microsecond time separation
  • Phase shifting interferometry
  • High spatial and temporal resolution
  • High sensitivity
  • Separation of steady and unsteady flow effects
  • Portable with flexible configurations

The Instrument Represents:

  • A major advance in the state of the art in flow diagnostics
  • A new and powerful tool for high-speed wind tunnels
  • A breakthrough in flow diagnostics
  • A new class of “next generation” instruments for the wind tunnel community