Ejection in Wind Tunnels. The Theory Explaining Pressure Losses in Subsonic Diffusers
Abstract
When testing an aircraft model in a wind tunnel the drag of the model itself requires only a low proportion of the wind tunnel compressor power- say the blockage ratio which is a few per cent. An almost equal proportion is lost in the balance i.e. 90% of the electric power consumed is spent to recover the total pressure loss in wind tunnel diffusers. Therefore it is crucially important to reveal mechanisms of the diffuser loss and predict it. Gas flow in a divergent diffuser is essentially multidimensional viscous often nonstationary and depends on flow nonuniformity at the diffuser entry station. These difficulties did not allow researchers to identity major processes in a diffuser with an (almost) optimum divergence angle and develop a rather clear, one-dimensional loss theory which could describe flow with general initial nonuniformity. Crocco had cast doubt on even the possibility of creating any one-dimensional theory for analyzing diffusers, nonetheless, he appreciated one-dimensional approximations and had succeeded in this area.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2002
- Accession Number
- ADA409242
Entities
People
- Yu. K. Arkadov