摘要:

We extend the technique of isolating and order reducing transformations for computing adiabatic invariants in finite‐degree‐of‐freedom Hamiltonian systems to the case of the non‐Hamiltonian modal representation of a wave equation with weak nonlinearities in a slowly varying domain. We exhibit the mechanism of resonant interactions for two or more normal modes whereby the associated actions change rapidly in a short period. In the Hamiltonian problem there are a number of global adiabatic invariants associated with each resonance. We derive conditions for which similar adiabatic invariants can be found for the non‐Hamiltonian case. The results are then verified by extensive numerical com

ISSN:0022-2526    

DOI:10.1002/sapm19847111

年代:1984

数据来源: WILEY

摘要:

Exact free streamline solutions are found for two dimensional inviscid incompressible flow past a single and a multiple flap wing using a hodograph method. It is shown that solutions do not exist for arbitrary shapes, but that a geometrical constraint must be satisfied between the shape of the wing and the angle of attack. High lift coefficients are obtained for both cases. These solutions model the flow situation for a wing claimed in the past to give high lift at low speed.

ISSN:0022-2526    

DOI:10.1002/sapm198471165

年代:1984

数据来源: WILEY

摘要:

Viscoelastic material at high temperature is subjected to a cooling process. The stresses built up in the body are determined from a system of equations containing a strongly temperature‐dependent viscosityη(T), where the temperatureTis given by the heat conduction equation. It is shown that for simple geometries such as infinite cylinders and spheres, the basic equations can be reduced to a single Volterra‐type integrodifferential equation, which is shown to have a unique solu

ISSN:0022-2526    

DOI:10.1002/sapm198471179

年代:1984

数据来源: WILEY