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Dear all,

I want to download some papers from the following International symposium " 14th International Symposium on Unsteady Aerodynamics, Aeroacoustics & Aeroelasticity of Turbomachines (ISUAAAT14) ". I don't know how to download papers as they are not available online and no DOI number. Does anybody know how to download papers from this? thanks in Advance

Hi 

I read 2 paper about unsteady supersonic flow.

1- Morino, Luigi. "A general theory of unsteady compressible potential aerodynamics." (1974).

(http://ntrs.nasa.gov/search.jsp?R=19750004821)

2- Garrick, Isadore Edward, and S. I. Rubinow. Theoretical study of air forces on an oscillating or steady thin wing in a supersonic main stream.

(http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA298725)

Morino used nonlinear unsteady compressible potential flow and Green function. Then he made some assumption such as small perturbation and eliminated nonlinear term on RHS. (see pages 39 & 45 for final formula)

In other hand, Carrick used linearized unsteady potential flow and fundamental solution (which is based on Green  function) and made his method.

both of these methods are based on small perturbation and Green function, but Morino has a second term which is not in Carrick's work. Albeit Morino said for symmetric supersonic edges, his formula is in agreement with Carrick's formula.

It means that, Morino's work is more general than Carrick.

Now my question is, both of them have same assumptions and method. What is difference in their works?

I think, there is difference in their methods which I have not noticed it.

Anyone has experience in this topic to clear difference between this two methods?

 Thank You

I'm particularly interested in predicting the flutter speed of a 3D aircraft using FEM for the structural analysis and panel methods for the aerodynamic force. I would like to find some theory/applications concerning modeling flexible structures by mode expansions in a panel method code in order to express the aerodynamic force by {F}=[A]{q}, where {q} are the generalized displacements and [A] is the generalized aerodynamic matrix. This matrix is a function of the "reduced frequency" k.

Which modes are controlling the flutter? What the flutter mechanism is and how can the flutter speed be increased? Any hint and examples to the questions above? Thanks

I have analysed the unsteady forces calculated by FAST v7 to get the periodical unsteady forces to check the fatigue due to them.

I got fn and ft for 30 station on the HAW blade of 7m length.

The time length was 151 seconds and step was 0.004 s.

My procedure was to get the max fn in each time step and assuming it is acting on the blade at this time neglecting the position and the other components to simplify my analysis.

I made fft analysis and got the periodical ones and I assumed that for the next 151 seconds these forces will repeat themselves.

The results of fft (Fn vs frequency) and fn in time domain is shown below

Can you tell me your opinion on this procedure?

I want to write a code related to the flutter of aeroelastic wing under unsteady load using doublet lattice method (DLM). I want a good reference with numerical examples or a book which learn me coupling doublet lattice method (DLM) with finite element method (FEM) step by step.

Recently, I have read some references applying proper orthogonal decomposition to solve unsteady aerodynamic problems. I'm very interested in this topic and really want to learn more about it. For now, I'm not sure how this method works, so, can anyone who is familiar with this topic give me some advice about starting in this field? Or some recommendations for related materials (books and references that may contain necessary mathematics background)? Thanks a lot!

PS: I'm familiar with linear algebra and basic matrix analysis, but I don't know much about control theory since I majored in aerodynamics.

In nature the smaller a flying beast is the faster it flaps its wings (birds and insects). In the literature it is shown that an important mechanism used to generate lift in small creatures is unsteady separation. Bubbles form on the leading edge and gradually grow as the point of reattachment moves rearwards. Whilst the bubble is growing the lift coefficient is very high: higher than steady flow aerofoils by up to a factor of 2. I think small, low Reynolds turbines (and compressors) ought to have unsteady flow of this type. Can anyone think of how to design a turbine with such an unsteady flow mechanism?

I am working on a research paper about the parked NREL Phase VI under wind shear profile.

As I have read, the pressure coefficients which are available in other articles for the parked condition are from one of the NRLE reposts (Unsteady Aerodynamics Experiment Phase VI: Wind Tunnel Test Configurations and Available Data Campaigns). However, when I look inside the report there is actually not such Cp data.

Hence, I decided to see if anyone could help me with the Cp data of the parked blade under the following conditions:

Alpha (@ 47%)= -1.48

Alpha (@ 47%)= 8.54

Alpha (@ 47%)=13.46

Alpha (@ 47%)=23.49.

I highly appreciate in advance if someone could send me the data or could help me about the way I can acquire it.

As usually the trend is a Courant number (CFL no) can only be used for a Transient( Unsteady) flow condition?