Wind tunnel

The closed-return Goettingen type wind tunnel has an open (round) test section of 1.1 m in diameter, 1.4 m in length, and is characterized by a free-stream velocity 10-40 m/s and by a turbulence level of 0.9%. Available instrumentation:

  • Pitot-static tube – the free-stream velocity is measured through a Pitot-static tube.
  • Hot-wire anemometry – The velocity measurements to obtain the boundary layer profiles and the wake field are carried out using an IFA AN 1003 A.A. Lab System hot-wire anemometry module. Single-wire and X-wire Dantec probes are moved in the x, y and z directions with an accuracy of 0.1 mm by means of a computer-controlled traversing system.
  • Pressure measurements – The pressures are measured using two Pressure Systems ESP-16HD miniature electronic pressure scanners. The scanners can be positioned inside the model with the relevant output cables passing through the support fairing.
  • Force measurements – six-component strain-gauge balance
  • Temperature measurements – thermocouple
  • Vorticity measurements – vorticity probe (vorticimeter)
  • Flow visualizations: cotton tufts, smoke, paints, liquid crystals.

Experimental and numerical study of separated flows:
A large contribution to the aerodynamic drag of a bluff body is given by the low pressures on its base, i.e. the surface lying within the separated wake. In order to develop strategies to decrease drag, a critical issue is the relationship between the base pressure and the flow parameters.

  • Mariotti A, Buresti G (2013) Experimental investigation on the influence of boundary layer thickness on the base pressure and near-wake flow features of an axisymmetric blunt-based body. Exp Fluids 54:1612
  • Mariotti A, Buresti G, Salvetti MV (2015) Connection between base drag, separating boundary layer characteristics and wake mean recirculation length of an axisymmetric blunt-based body. J Fluid Struct 55:191–203
  • Mariotti A (2018) Axisymmetric bodies with fixed and free separation: base pressure and near-wake fluctuations. J Wind Eng Ind Aerodynamics 176:21–31

Flow separation delay and drag reduction through contoured transverse grooves:
Flow control is of great importance in many engineering applications to attain desired characteristics. Several investigations have been carried out aimed at assessing the performance of contoured transverse grooves as a passive method to delay boundary layer separation

  • Mariotti A, Buresti G, Gaggini G, Salvetti MV (2017) Separation control and drag reduction for boat-tailed axisymmetric bodies through contoured transverse grooves. J Fluid Mech 832:514–549

Research group
RAR: Giovanni Lombardi,
Alessandro Mariotti,
Elena Pasqualetto