Test Facilities

Cold Acoustic Test-rig
The test-rig consists of two measurement sections with the test object in-between and anechoic terminations at the ends. In its modular construction it can be equipped with a circular or square cross-section test duct. All tests are performed under atmospheric conditions Circular cross-section: Aluminium tube with 140mm diameter Cut-on frequency of the first higher order mode 1433 Hz Mach number of the main flow, up to Ma = 0.1 Bias flow up to 600 kg/h of air possible Microphones can be mounted at 10 rings with 8 circumferential positions each Various mountings for cylindrical test objects Square cross-section: Square cross-section (80mmx80mm) made of acrylic glass Cut-on frequency of the first higher order mode 2200 Hz Mach number of the main flow, up to Ma = 0.27 Total of 10 axial microphone positions in both sections Additional 10 microphone positions opposite the liner Optical access Atmospheric Combustor Rig fused quartz glass or stainlless steel combustion chamber with 100 mm inner diameter optical access for laser diagnostic swirled dual air flow nozzle with methane as fuel exchangeable outlet nozzle with different throat diameter exhaust duct with 1000 mm lenght and 100 mm inner diameter  12 probe microphones can be flush mounted on the exhaust duct at 3 axial and 4 circumferential positions reflection minimizing termination maximum thermal power up to 40 kW maximum Mach number in the outlet nozzle is 0.8  „Glas nozzle“ for optical access at combustion chamber outlet, investigation of entropy noise Automatic control with independent adjustment of air and fuel Wide working range with lambda=0.8-1.8 (lean combustion)	Cold Acoustic Test-Rig with circular cross-section test duct and anechoic terminations . Test duct with square cross-section   Exhaust Duct .
Entropy Wave Generator (EWG) / Vortex Wave Generator (WWG) test rig for investigation on indirect combustion noise
Tube flow with convergent – divergent nozzle Tube with 30 mm inner diameter before and 40 mm after the nozzle Flow medium : air Heating module to generate Entropy waves electrically Generation of Vortex Structures by air injection Exchangeable tube sections Optical access for laser diagnostics Maximum Mach number M=1.0 6 measurement positions for flush-mounted microphones, 4 of them downstream of the nozzle in a tube section of 1000 mm length Anechoic termination	Entropy Wave Generator / Vortex Wave Generator test rig . Sketch of the EWG /WWG