Experimental investigation of the influence of the flow structure on the aerodynamic coefficients of the IXV vehicle

In the frame of the ESA Future Launchers Preparatory Programme (FLPP) an experimental re-entry phase of the Intermediate eXperimental Vehicle (IXV) configuration has been conducted in the DLR hypersonic wind tunnel H2K in Cologne. Tests have been carried out at Mach 6.0 and 8.7 with different flap deflection angles and the angle of incidence varied continuously between 20° and 55° to investigate the flow topology as well as the aerodynamic forces and moments and the surface pressure distribution. The experimental data show that depending on the combination of the flap deflection angle and angle of incidence the complex flow structure in the vicinity of the flaps (i.e. the shock/shock and shock/boundary layer interaction causing flow separation and reattachment) can influence the vehicle aerodynamic coefficients significantly

Experimental investigation of the influence of the flow structure on the aerodynamic coefficients of the IXV vehicle

In the framework of the ESA Future Launchers Preparatory Program (FLPP) an experimental study on the aerodynamic behavior during the re-entry phase of the Intermediate eXperimental Vehicle (IXV) configuration was conducted in the DLR hypersonic wind tunnel H2K in Cologne. Tests were carried out at Mach 6.0 and 8.7 with different flap deflection angles and the angle of attack varied continuously between 20◦ and 55◦ to investigate the flow topology as well as the aerodynamic forces and moments and the surface pressure distribution. The experimental data show that depending on the combination of the flap deflection angle (δL/R) and angle of attack (α) the complex flow structure in the vicinity of the flaps significantly influences the vehicle’s aerodynamic coefficients. An analysis of this shock/shock and shock/boundary layer interaction causing flow separation with reattachment is performed

An Experimental Study on Aerothermal Heating of the IXV Configuration During Reentry

In the framework of the ESA FLPP program an experimental investigation of the aerothermodynamic phenomena on the IXV configuration during reentry phase has been conducted in the hypersonic windtunnel H2K at DLR Cologne. To study the control behavior of the vehicle with flaps at different flight conditions, a variation of the flap deflection and the angle of attack have been applied. Tests have been carried out at Mach 8.7 and three different Reynolds number steps. The test duration was up to 20 seconds. The model is made of a material with low thermal conductivity, in order to measure the surface temperature distribution by means of IR thermography and to avoid any heat dissipation inside the structure. Using this data the heat flux rate has been determined taking into account temperature-dependent material characteristics, assuming a semi infinite wall and radiative cooling to the environment. The flow topology has been analyzed using Schlieren images. Depending on the combination of the flap deflection angle and angle of attack the experimental data show a significant influence of the Reynolds number on the shock-shock and shock-boundary layer interactions, flow separation and its re-attachment, which lead to a completely different aerothermal heating on the flap

Characteristics of 542 consecutive pneumonectomies from 2003 to 2007 (discovery set).

<p>ASA = American Association of Anesthesiologists. FEV1 = median forced expiratory volume in 1 second. FVC = median forced vital capacity.</p><p>*Pneumonectomies with resections of the atrium, diaphragm, chest wall or superior vena cava were defined as other extensions.</p><p>Characteristics of 542 consecutive pneumonectomies from 2003 to 2007 (discovery set).</p

Characteristics of 232 consecutive pneumonectomies from 2008 to 2010 (validation set).

<p>ASA = American Association of Anesthesiologists.</p><p>Characteristics of 232 consecutive pneumonectomies from 2008 to 2010 (validation set).</p

Final risk prediction model of in-hospital mortality after pneumonectomy in the discovery set based on data from 542 consecutive pneumonectomies that were performed between 2003 to 2007.

<p>CI = confidence interval.</p><p>¶ High leukocyte counts were not considered “yes” if related to steroids or immunosuppression with no clinical signs of infection.</p><p>Final risk prediction model of in-hospital mortality after pneumonectomy in the discovery set based on data from 542 consecutive pneumonectomies that were performed between 2003 to 2007.</p

Selected studies of preoperative risk factors for mortality after pneumonectomy.

<p>FEV1/ FVC = forced expiratory volume in 1 second/ forced vital capacity; DLCO = diffusion capacity of lung to carbon monoxide.</p><p>Selected studies of preoperative risk factors for mortality after pneumonectomy.</p

Definitions of the comorbidities according to the International Classification of Diseases (ICD) version 10.

<p>Definitions of the comorbidities according to the International Classification of Diseases (ICD) version 10.</p