FLUTTER

Testing flutter on thermal insulation panel

Project duration: 2011 to 2012

Project manager VZLÚ: Karel Patočka

Project manager LKE: Martin Komárek

The goal of the project was flutter assessment of jettisonable versatile thermal insulation panels of upper cryogenic stage of a launcher. VZLÚ and LKE companies mutually cooperated in the course of the project.

VZLÚ performed design, calculations and experiments on aeroelastic scaled models based on similarity laws. Each scaled model of the panel including fixture was designed in Catia 3D modeller. CFD and flutter calculations proved sufficient flow quality and flutter occurrence for particular Mach number. The models were measured in high speed wind tunnel in subsonic, transonic and supersonic regimes. Aerodynamic and aeroelastic experimental results, mainly pressures and accelerations, were obtained by measuring rigid duralumin panels and flexible composite panels. Experimental results of the latter scaled models showed good agreement with the calculated figures.

LKE focused on development of computational methodology to perform an assessment of panel flutter response with a possibility of extension to other physical effects. The other part of activity was focused on identification of flutter boundary of full scale panel. LKE proposed and verified computational methodology based on simultaneous solution of external aerodynamics and structural dynamic response in time domain. The proposed complex methodology is not widely used in space design, therefore an effort was spent to identify a range of validity, verify and correlate results with wind tunnel testing data. The real geometry based solution enabled to determine the flutter response and critical regimes during the launcher takeoff. Based on the analyses results, the effect of main design system parameters was mapped and the significance of aeroelastic instability was confirmed.

All VZLÚ and LKE results could be used to assess full scale panel behaviour during launch to orbit, to find stability level and to identify critical flight regime. An important part is a feedback to design team to further improve and optimize design with regards of flutter effects.

Aeronautical and Research Test Establishment (VZLÚ)

VZLÚ is a national centre for research, development and testing in aeronautics and astronautics. The major multidisciplinary fields of VZLÚ include: aerodynamics, structure strength and durability, material and corrosion engineering, composite materials and technologies, accredited testing and space instruments for satellites. VZLÚ also contributes to progress of automotive, rail, defence, security and power industry and civil engineering.

LK Engineering (LKE)

The company focuses on modelling of mechanical systems involving structural, thermal and fluid dynamic effects and it also provides expertise and design consultation for industrial partners. In the field of space technologies LKE specialises on the design of space system components.

Co vám účast v projektu přinesla?

“Participation in the project enabled VZLÚ to apply and expand knowledge and capabilities in the field of panel flutter. A huge benefit for the company was also the opportunity to contribute to such a project itself, because VZLÚ started to cooperate with key partners in the demanding space segment of the next generation launcher.”

“For LKE it was very exciting experience just to be part of a team of key players in launcher business and working on the solution of an interesting problem. Our responsibility within the project allowed us to see the complicated process of pushing an innovative method of computational approach and convince people to trust it. Successful completion of the project provides important links and references and identifies several areas of potential application of our new methodology.”