Reaktive Strömungen (Flammen) und nicht reaktive Strömungen
CFD-Simulation von Flammen brennbarer flüssiger und fester Stoffe
Berechnung und Messung zeitabhängiger Konzentrations-, Temperatur- und Geschwindigkeitsfelder sowie der Wärmestrahlung und von periodischen Eigenschaften
Holografische real-time Durchlichtinterferometrie zur Sichtbarmachung und Analyse organisierter (dissipativer) Strukturen in reaktiven Strömungen (Flammen) und nicht-reaktiven Strömungen
Digitale Bildanalyse von transienten Interferenzstreifenmustern und Kurzzeit-VIS-Strahldichtestrukturen von Flammen
Simulation und Messung von Explosionsgrenzen gefährlicher, brennbarer und/oder zerfallsfähiger technischer Gas/Dampf/Inertgas-Gemische in Abhängigkeit von Druck und Temperatur
Diagnostics and CFD Simulation of buoyant reacting and non-reacting flows
pool fires, tank fires
non-reacting buoyancy driven flows
Diagnostics:
High-speed photography
Thermographic camera system with a video mixing unit
Digital image analysis
Pyroelectric and ellipsoidal radiometry
Gas chromatography
Large scale pool fires
Pool diameters: 1 m < d < 25 m; Fuels: LNG, n-pentane, premium gasoline, regular grade gasoline, diesel, JP-4, Di-tert-butyl peroxide (DTBP)
From measured instantaneous thermographic images a logarithmic pdf of SEP is derived. Thermal radiation model OSRAMO II is validated for sooty large pool fires.
From CFD simulation instantaneous isotherms, isosurfaces of temperature, SEP, flow fields and irradiances E(t, Δy) are calculated.
Methane ( d = 1 m )
Flow field and isotherms, kerosene (d = 20 m)
Small scale fires
Tank diameter: 1 cm < d < 25 cm: Fuels: hydrocarbons (methane to heptane), alcohols, acetaldehyde, acetone, diethyl ether, acetic acid, -ester, benzene, hydrogen
With a holographic real-time interferometer organized structures of the mass density field and luminous flame are visualized.
n-hexane (d = 4.6 cm)
n-hexane (d = 4.6 cm), at a height between 25 – 50 cm
n-hexane (d = 4.6 cm), at a height between 50 – 75 cm
From interferometric patterns oscillation phenomena are determined.
Measurements of temperature, concentration of stable molecules and flow velocities are carried out.
Methane tank fire (d = 4.6 cm)
From interferometric patterns instantaneous radial mass density and temperature profiles are calculated by using the Abel inversion.
Small scale non-reacting flows
Pool diameter: 1 cm < d < 25 cm; Fluids: helium, hot air
With a holographic real-time interferometer organized structures in the mass density field integrated along the light path are visualized.
hot air plume (d = 4,6 cm, 498°C)
Helium plume (d = 4,6 cm, 20°C)
CFD-simulated sections of instantaneous isolines of mass density and the mass density field integrated along the z-axis, helium flow (d = 4.6 cm, 20°C)
