Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Comparison of flutter calculation methods based on ground vibration test result

Comparison of flutter calculation methods based on ground vibration test result A low-cost but credible method of low-subsonic flutter analysis based on ground vibration test (GVT) results is presented. The purpose of this paper is a comparison of two methods of immediate flutter problem solution: JG2 – low cost software based on the strip theory in aerodynamics (STA) and V-g method of the flutter problem solution and ZAERO I commercial software with doublet lattice method (DLM) aerodynamic model and G method of the flutter problem solution. In both cases, the same sets of measured normal modes are used.Design/methodology/approachBefore flutter computation, resonant modes are supplied by some non-measurable but existing modes and processed using the author’s own procedure. For flutter computation, the modes are normalized using the aircraft mass model. The measured mode orthogonalization is possible. The flutter calculation made by means of both methods are performed for the MP-02 Czajka UL aircraft and the Virus SW 121 aircraft of LSA category.FindingsIn most cases, both compared flutter computation results are similar, especially in the case of high aspect wing flutter. The Czajka T-tail flutter analysis using JG2 software is more conservative than the one made by ZAERO, especially in the case of rudder flutter. The differences can be reduced if the proposed rudder effectiveness coefficients are introduced.Practical implicationsThe low-cost methods are attractive for flutter analysis of UL and light aircraft. The paper presents the scope of the low-cost JG2 method and its limitations.Originality/valueIn comparison with other works, the measured generalized masses are not used. Additionally, the rudder effectiveness reduction was implemented into the STA. However, Niedbal (1997) introduced corrections of control surface hinge moments, but the present work contains results in comparison with the outcome obtained by means of the more credible software. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Aircraft Engineering and Aerospace Technology Emerald Publishing

Comparison of flutter calculation methods based on ground vibration test result

Download PDF
11 pages

Loading next page...
 
/lp/emerald-publishing/comparison-of-flutter-calculation-methods-based-on-ground-vibration-sOiBYymHiN
Publisher
Emerald Publishing
Copyright
© Emerald Publishing Limited
ISSN
1748-8842
DOI
10.1108/aeat-03-2018-0102
Publisher site
See Article on Publisher Site

Abstract

A low-cost but credible method of low-subsonic flutter analysis based on ground vibration test (GVT) results is presented. The purpose of this paper is a comparison of two methods of immediate flutter problem solution: JG2 – low cost software based on the strip theory in aerodynamics (STA) and V-g method of the flutter problem solution and ZAERO I commercial software with doublet lattice method (DLM) aerodynamic model and G method of the flutter problem solution. In both cases, the same sets of measured normal modes are used.Design/methodology/approachBefore flutter computation, resonant modes are supplied by some non-measurable but existing modes and processed using the author’s own procedure. For flutter computation, the modes are normalized using the aircraft mass model. The measured mode orthogonalization is possible. The flutter calculation made by means of both methods are performed for the MP-02 Czajka UL aircraft and the Virus SW 121 aircraft of LSA category.FindingsIn most cases, both compared flutter computation results are similar, especially in the case of high aspect wing flutter. The Czajka T-tail flutter analysis using JG2 software is more conservative than the one made by ZAERO, especially in the case of rudder flutter. The differences can be reduced if the proposed rudder effectiveness coefficients are introduced.Practical implicationsThe low-cost methods are attractive for flutter analysis of UL and light aircraft. The paper presents the scope of the low-cost JG2 method and its limitations.Originality/valueIn comparison with other works, the measured generalized masses are not used. Additionally, the rudder effectiveness reduction was implemented into the STA. However, Niedbal (1997) introduced corrections of control surface hinge moments, but the present work contains results in comparison with the outcome obtained by means of the more credible software.

Journal

Aircraft Engineering and Aerospace Technology – Emerald Publishing

Published: Mar 13, 2019

Keywords: Flutter; DLM; Flaperon; GVT; Strip theory in aerodynamics; T-tail

References

  • Proportional optimal orthogonalization of measured modes
    Baruch, M.
  • Binary flutter calculation with theoretical and empirical aerodynamic derivatives for a wing-control surface system in two-dimensional incompressible flow
    Bergh, H.; Tijdeman, H.
  • Aeroelastic certification of light sport aircraft according to LTF regulation
    Cecrdle, J.; Hlavaty, V.
  • Critical flutter speed of sailplanes calculated for high altitude. Examples of computation
    Chajec, W.C.
  • Flutter calculation based on GVT-results and theoretical mass model
    Chajec, W.; Seibert, T.
  • Aeroelastic calculation of innovative non-conventional aircraft with swinging canard surface
    Chajec, W.
  • Flutter computation based on ground vibration test results and mass data
    Chajec, W.; Petrova, V.M.
  • Obliczenia flatteru prostokątnego płata ze sterem za pomocą MSC NASTRAN i ZONA ZAERO – porównanie z wynikami badań w tunelu aerodynamicznym
    Chajec, W.; Dziubiński, A.
  • Modal approach in the fluid-structure interaction in aerospace
    Chajec, W.; Dziubiński, A.
  • Comparison of flutter calculation methods based on GVT results
    Chajec, W.
  • Aeroelastic analysis of remotely controlled research vehicles with numerous control surfaces
    Goraj, Z.; Chajec, W.
  • An approximate true damping solution of the flutter equation by determinant iteration
    Hassig, H.J.
  • “Ground Vibration Tests of Airplane Pipistrel Virus SW 121”
    Lorenc, Z.; Cieślak, S.; Krzymień, W.; Chajec, W.
  • Flutter analysis of icare 2
    Niedbal, N.
  • “Methodology and Software for Flutter Analysis of Aircraft, Report No.1, Flutter Computation Methodology”
    Nowak, M.
  • “Flutter Analysis of Light Aircraft Methodology”
    Nowak, M.; Potkański, W.
  • Model updating of finite element model using optimisation routine
    Prananta, B.; Kanakis, T.; Vankan, J.; van Houten, R.
  • Information
  • MSC NASTRAN aeroelastic analysis. User’s guide
    Rodden, W.P.; Johnson, E.H.
  • The aeroelastic stability analysis – a practical interval approach of uncertainty aspects in modelling of aircrafts
    Schwochow, J.
  • On simplified analytical flutter clearance procedures for light aircraft
    Kießling, F.