Project News

• High-Speed wind tunnel test campaign at TsAGI T-128 transonic wind tunnel
• Hisac Low-Speed wind tunnel test campaign at RUAG Aerospace
  
• High-Speed wind tunnel test campaign at ONERA-S2

High-Speed wind tunnel test campaign at TsAGI T-128 transonic wind tunnel

1. Dates and location of the tests:
The tests have been performed in TsAGI’ transonic wind tunnel T-128 at Zhukovsky (Russia) during 7 days from 28th of November to the 6th  of December 2007.

The test section size of this facility is 2.75 by 2.75 meters and the maximum possible speed is M=1.4.

Figure 1 – HISAC model in T-128 test section #1

2. Test objectives:

The tests of this campaign were dedicated to the following investigations:

1. - investigate the performance of the baseline aircraft configuration in transonic and low supersonic regimes
2. - investigate the impact of slats on drag polar at transonic regime
3. - investigate the impact of trim on drag polar at transonic conditions (with/without small canard planes or HTP)
4. - investigate wing performance around buffet onset
5. - investigate the dynamic pressure effect on aerodynamic characteristics
6. - evaluate the nacelle internal drag at different free stream conditions
7. - produce the best quality of the data including a full set of corrections on longitudinal coefficients (lift, drag and pitching moment)at high CL (before and after buffet onset).

Figure 2 – oil flow visualization

The model was equipped with 65 pressure taps in order to make cross-checks with CFD.
During the testing 39 runs were performed including force measurements, internal nacelle mass flow rate and drag evaluations with rakes, oil and acenaphthene flow visualization.

3. Preliminary conclusions

The tests that have been carried out provided the following results: − aerodynamical data are obtained for cross-check with CFD and aerodynamical database generation

• − Favorable comparison with analogous data obtained in the ONERA Modane S2 facility
• − Data for the nacelle internal mass flow rate are obtained that can be compared with alternative evaluation of these data obtained by alternative ONERA approach
• − Data for the nacelle internal drag coefficient are obtained
• − High accuracy of the results obtained is demonstrated
• − At aircraft level, preliminary analysis of the data doesn't show any major concern in transonic region. Results are still under investigation.

Hisac Low-Speed wind tunnel test campaign at RUAG Aerospace

1. Dates and location of the tests

The tests have been performed in the low-speed wind tunnel facility of RUAG Aerospace at Emmen (Switzerland) during 5 days from the 5th to the 9th of November 2007.

The test section size of this facility is 5 by 7 meters large and the maximum speed possible is 68 m/s.

Figure 1 - HISAC model in LWTE RUAG Aerospace test section.

2. Test objectives

The tests of this campaign were dedicated to the following investigations:

• maximum lift performance at landing
  
• lift to drag ratio performance at take-off
  
• comparison of different flaps (slotted and plain ones)
  
• canard effects on longitudinal trim
  
• ailerons and elevons effectiveness
  
• slat and flap settings in order to optimize landing and take-off configurations
  

The model was equipped with 101 pressure taps in order to make correlations with the best flap and slat settings, and also to make cross-checks with CFD.

Oil-flow visualisations were also made, and about 90 runs were performed during 40 hours of effective testing.

Figure 2 - Leading edge slats extended	Figure 3 - Plain and slotted flaps extended on trailing edge

3. Preliminary conclusions

These tests allowed to demonstrate good low speed aerodynamic behaviour of a SSBJ which matches the specifications set by the consortium at the beginning of the Project and which is also highly constrained by environmental specifications.

The main features of this configuration shapes are:

• Low boom characteristics
  
• High by-pass-ratio engines to decrease noise constraints
  
• High speed shaping (tested during last wind tunnel tests in ONERA S2 and to be confirmed in next TsAGI T128 campaign)
  

High-Speed wind tunnel test campaign at ONERA-S2

Three wind tunnel test campaigns are planned by the HISAC project Consortium before the end of 2007:

• low-speed:
  
  • test at RUAG, Emmen (Switzerland)
• high-speed:
  
  • transonic and supersonic (up to Mach 1.4): test at TsAGI T-128 (Russia)
    
  • Mach 1.5 to 1.8 and additional testing below Mach 1.3: test at ONERA S2 Modane (France)

During last week of June 2007, the first HISAC high-speed wind tunnel test campaign took place at ONERA S2 facility in Modane.
The main objectives of this test were to :

• obtain drag sensitivities to engine-integration options, engine size and spillage
  
• identify impact of control surface options on drag polar
  
• validate the transonic L/D "optimization" of wing leading edge camber

Three different engine integration solutions were designed as well as a glider configuration (see Figure 1 below) and a laminar wing (see Figure 3).

Config. 1		Config. 2
Engine BPR ~3.5		Engine BPR ~1.5
Config. 3		Config. 4
Engine BPR ~1.5		"Glider"
Figure 1 - The four HISAC model configurations

This model has also interchangeable leading edges as well as canards and horizontal tail planes.
All these model configurations were successfully tested in transonic and supersonic regimes up to Mach 1.8 (see Figures 2 & 3 below).

ONERA S2 transonic test section		ONERA S2 supersonic test section
Figure 2 - HISAC model in ONERA S2 transonic (left) and supersonic (right) test section

Figure 3 - HISAC model with laminar wing in ONERA S2 supersonic test section

Wind tunnel test (WTT) data will now be used to validate and calibrate computational fluid dynamics (CFD) tools and aerodynamic sensitivity models. WTT data together with calibrated CFD data will be used to build and improve parametric models for MDO processes.