The LEAT possesses a 2D Laser Doppler Anemometry (LDA) system. LDA has proven effective for the fast and efficient determination of velocities and turbulence parameters. For the functionality of this measurement technique, aside from optical access, a sufficient quantity of small particles must be present in the flow region. These particles (known as seeding) should ideally follow the flow without slippage. For LDA application, two laser beams of defined wavelengths are crossed at the focal point of a collecting lens for each spatial direction to be detected, forming the intersection or measurement volume. This volume exhibits an interference stripe pattern. When a tracer particle is transported by the flow through the intersection volume, it reflects the laser beams at a frequency dependent on the distance of the interference stripes and the particle’s velocity. This frequency is detected in the backscatter mode and converted into velocity. Through statistical analysis, the measured signals can be used to determine average velocities, standard deviations, and other turbulence parameters.

Contact: B. Sc. Linus Pölling

To extend the capabilities of LDA, Phase Doppler Anemometry (PDA) determines particle and droplet size distributions. The measurement volume generated by the laser beams of the LDA system is observed in PDA using an additional receiving optic that detects the phase Doppler frequency. The LEAT has two systems available for the use of LDA/PDA measurement techniques. In addition to a permanently installed LDA system in a test laboratory, there is a mobile LDA/PDA apparatus with a compact, modular design of lasers and transmission and reception optics, which can be quickly and efficiently set up at external measurement sites.

Contact: B. Sc. Linus Pölling

For industrial applications, the Chair of Energy Plant and Energy Process Engineering uses an LDA system with a water-cooled probe. This allows for measurements in flows subject to high thermal and mechanical stress, such as in waste incineration plants, pulverized fuel combustion systems, or spray roasting reactors.

Contact: B. Sc. Linus Pölling

The chair possesses extensive gas analysis capabilities, which include:

• NH₃ (Microwave Analyzer)
• C_XH_Y (Flame Ionization Detector)
• O₂ (Paramagnetic Measurement Principle)
• H₂ (GC in combination with Thermal Conductivity, TCD)
• NO and NO₂ (Chemiluminescence)
• CO, CO₂, SO₂, and N₂O (Infrared Absorption, IR)
• Up to 32 different species with FTIR

Contact: M. Sc. Christoph Yannakis and M. Sc. Erik Freisewinkel

At LEAT, there is a measurement system for the optical analysis of reacting dust-sized particles. This stereoscopic Camera System for Optical Thermography (SCOT) is based on two-color pyrometry and can additionally detect "cold," non-ignited particles through shadowgraphy.

The SCOT system, equipped with four intensified CCD cameras, captures different physical properties of the particles. Cameras 1 and 2 form the pyrometry unit and are supported by camera 3 for stereoscopic particle shape detection. Camera 3 is positioned at a 90° angle to cameras 1 and 2 and operates in double exposure mode, with the second exposure used for 1D Particle Tracking Velocimetry (PTV). Camera 4 is dedicated to shadowgraphy.

Contact: M.Sc. David Tarlinski

The LEAT has various high-speed cameras, including:

• MotionBLITZ EoSens Cube7, max. 200.000 fps
• Imacon 468, max. 100-200 Mfps

Contact: M. Sc. Phil Spatz

The LEAT has various infrared cameras for measuring surface temperatures. The cameras differ in resolution and frame rate, as well as in their detectors.

1. InfraTec VarioCAM® HDx head 600

• Temperature range: (-40 ... 600) °C
• Measurement accuracy: ±2 K (0 ... 100) °C; ±2 % (<0 or >100) °C
• Resolution: 640 x 512 IR pixels at 30 Hz

2. InfraTec ImageIR® 8380 hp MF

• Temperature range: (-10 ... 300) °C
• Measurement accuracy: ±1 %
• Resolution: 640 x 480 IR pixels at 355 Hz

3. Jena Optik VarioTherm® head II (now InfraTec)

• Temperature range: (-25 ... 1200) °C
• Measurement accuracy: ±2 %
• Resolution: 256 x 256 IR pixels at 50 Hz

Contact: M. Sc. Phil Spatz

The LEAT possesses a so-called Hot-Disc measurement device. In this device, a flat, circular sensor is placed between two sample pieces and heated in a controlled manner. From the measurement of the temporal temperature changes at the sensor, the thermal conductivity, temperature conductivity, and specific heat capacity can be determined without additional knowledge of the thermophysical properties of the sample.

Contact: M.Sc. Matthias Tyslik