Laboratory of Heat and Mass Transfer

Head of Laboratory: Dr. Zdeněk Trávníček

The laboratory encompasses expertise in heat and mass transfer, fluid dynamics, fluidics and microfluidics. Specific missions include passive and active control of flow and temperature fields, intensification of heat and mass transfer in forced convection (impinging and synthetic jets, wakes).
 

Staff

Research Scientists
Assoc. Prof. Alexander Fedorchenko
Prof. Václav Tesař
Postdoctoral Researchers
Dr. Petra Dančová
Dr. Josef Kordík
Students
Ing. Zuzana Broučková

Visualizations obtained in the laboratory:

Synthetic jets: phase locked visualization and phase averaging of the velocity measurement Synthetic jets

Phase locked visualization and phase averaging of the velocity measurement

Credits: J. Kordík, Z. Trávníček



Lokální přestup tepla na steně Local heat transfer

produced by (the above animated) synthetic jet. The experiment was carried out using the naphthalene sublimation technique in the field laboratory in Nový Knín. Using the heat/mass transfer analogy the experimental mass transfer data were transformed into the Nusselt number distribution shown in the figure.



Visualization of the von Kármán vortex street on cooled cylinder Visualization of the von Kármán vortex street

at temperature T = 144.5°C, Re = 61

(a) Isothermal case T* = TW/T = 1.00

(b) Cooling of the cylinder (T*=0.70, Reeff=71) causes increasing of the vortex shedding frequency



Jet bistability

Two-slot impinging jet demonstrates bistability and hysteresis of flowfields: boundary conditions alone cannot determine the flowfield uniquely, because the flow pattern (A or B) depends on flowfield history. Flow field assumption (top figures) and confirmation by flow visualization (bottom figures).


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