CFD Case Studies

Air Conditioning Study with Long-Range Nozzles in the Depatrure Hall of a new Airport Terminal Building

The study aims to control the adequacy of the selected HVAC system in extreme cooling-heating conditions (maximum flow and maximum loads) in order to achieve the desired temperature and thermal comfort. The latter is evaluated by satisfying the criteria for temperature and velocity at average human height (z = 1.8m).

Airport Terminal - 3D view

Airport Terminal - 3D view

Airport Terminal – CAD section

The heating-cooling system delivers air-conditioned air through long-range nozzles located 9m above the floor of the room and 1.6m apart. The desired room temperature is 26 ° C in the case of cooling and 20 ° C in the case of heating. Returning air, leaving at a temperature equal to that of the space, is carried out through a longitudinal slot at a height of about 5m and its associated collection box (plenum).

Methodology:

  • Unsteady Navier-Stokes average flow equations for uncompressed flows coupled to the heat convection equation in space.
  • The variation of density relative to the variation of temperature is calculated based on the Boussinesq hypothesis and the corresponding buoyancy terms are entered into the momentum equations.
  • For modeling of turbulence, the model of two k-ω / SST equations is used, which gives exact results for flows with large recirculation ranges.
  • The integration of the equations is performed in finite volumes that are defined around the computational nodes of an unstructured, hybrid arithmetic mesh.
  • Spatial discretization of convective terms with second order accurate scheme.

Geometrical modeling, discretization

497.255 nodes and 2.497.255 tetrahedral elements.

2 regions (near solid walls and in the core of the space) with different resolution properties.

Unsteady solution with time step Δt=0.01sec

Airport Terminal - geometrical model

Airport Terminal - numerical mesh

Airport Terminal - numerical surface mesh

Results, Cooling Ventilation case

Cooling Ventilation Streamlines

Isothermal surfaces

Temperature distribution at z=1.8m

Velocity distribution at z=1.8m

Results, Heating Ventilation case

Heating Ventilation Streamlines

Isothermal surfaces

Temperature distribution at z=1.8m

Velocity distribution at z=1.8m

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