STARCS Air Inlet Simulation 

Testing of air inlet systems in wind tunnels is of considerable importance for airframe/engine integration. A special air inlet model, equipped with properly scaled inlet lip and inlet duct geometry, is tested at different model attitudes and inlet mass flow rates. At the position of the compressor (Aerodynamic Interface Plane, AIP), the quality of the air is investigated by measuring the distribution of total pressure (both steady-state as well as time-variant) by means of a cell with a number of total pressure tubes and miniature pressure transducers (e.g Kulites). The total pressure distributions give a clear picture of the inlet losses and also the degree of distortion; these quantities are of significant importance for the assessment of the performance of the intended engine/air inlet combination. During the last ten years STARCS (former FOI/FFA) has developed the capability to perform air inlet tests in the transonic wind tunnel T1500 (L/W/H: 4/1.5/1.5 m). The air extraction through the inlet is accomplished by means of an ejector (driven by compressed air) located in the wind tunnel diffuser downstream of the choke section (see figure on opposite side). The air mass flow rate is controlled by means of a valve and measured by a Venturi nozzle. Before entering the Venturi the air is conditioned by a flow straightener and also by having a long onset distance with a straight pipe. At present two ejector sizes are available, with the largest ejector being capable to extract about 15 kg/s at 5 bar total pressure in the wind tunnel.




Two different mass flow rate valves have been designed and tested, as well as several Venturi nozzles for different mass flow rate regimes. There are several options available for the customer in testing air inlet models in T1500. E.g. it is possible to execute step-and-pause measurements at preselected model attitude angles and at constant corrected mass flow rate through the inlet. In this mode the mass flow rate is controlled by feedback of the measured AIP total pressure average to the control system for the valve. Another option is to vary the corrected mass flow rate at constant model attitude. In addition to providing air inlet testing at high Reynolds numbers in T1500, STARCS also can offer help with design and manufacturing of air inlet models according to customers’ specifications, as well as necessary instrumentation.

Technical Specifications

 

Total pressure distribution at aerodynamic interface plane expressed as ptot / ptot,¥:

 

M¥ = 0.85
ReDAIP=7.0×106 (about 55% of full scale Re)

 

ptot / ptot,¥:

 

Main Features

STARCS has the capability to perform air inlet tests in the transonic wind tunnel T1500. Testing of air inlet systems in wind tunnels is of considerable importance for airframe/engine integration.
 
 

Related Information

T1500 - Transonic Wind Tunnel

T1500 is suited both for testing of high speed air- and spacecraft testing.
 
 

Store Release Simulation

An additional highly agile motorized arm attached to the ordinary model sting pod allow for sophisticated store release simulation.
 
 
LT1 - STARCS Low Speed Wind Tunnel
STARCS low speed wind tunnel is a multipurpose aerodynamic wind tunnel, capable of testing not only all sorts of aircraft models but also almost any type of transportation, large buildings and wind turbines.