Multiphase flows

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Turbulent dilute jet-sprays laden with evaporating droplets

Turbulent jet-sprays are complex multiphase flows where two distinguished phases present mutually exchanging mass, momentum and energy. It is widely existing in natural phenomena as well as industrial applications, like combustion systems. Focusing on this physical phenomenon, we are employing Direct Numerical Simulations (DNS) to advance the current understanding of the dispersion and evaporation behaviors of inertial droplets within a dilute regime. We identified mechanisms regulating the formation of droplets clusters at different spray regions, and demonstrated the insufficiency of classical d-square law in accurately predicting droplets vaporization.


  • Dalla Barba, Federico, Jietuo Wang, and Francesco Picano. “Revisiting D 2-law for the evaporation of dilute droplets.” Physics of Fluids 33.5 (2021): 051701.
  • Wang, Jietuo, Federico Dalla Barba, and Francesco Picano. “Direct numerical simulation of an evaporating turbulent diluted jet-spray at moderate Reynolds number.” International Journal of Multiphase Flow 137 (2021): 103567.
  • Dalla Barba, Federico, and Francesco Picano. “Clustering and entrainment effects on the evaporation of dilute droplets in a turbulent jet.” Physical Review Fluids 3.3 (2018): 034304.

Virus transmission through respiratory droplets

Pathogen-bearing droplets exhaled during respiratory events such as breathing, speaking, coughing and sneezing are the main source in transmitting infectious diseases like SARS-Cov-2. It is no doubt that their fate in the turbulent humid clouds determines the tempol-spatial distribution of virus included so as to affect the infection risk eventually. We are simulating and modeling respiratory jet-sprays laden with polydisperse droplets utilizing both high-fidelity simulations and low-order modeling approaches. Our findings provide clear information and effective tools on helping policymakers to design guidelines.


  • Wang, Jietuo, et al. “Modelling the direct virus exposure risk associated with respiratory events.” Journal of the Royal Society Interface 19.186 (2022): 20210819.
  • Wang, Jietuo, et al. “Short-range exposure to airborne virus transmission and current guidelines.” Proceedings of the National Academy of Sciences 118.37 (2021).