Scattering from defects in buried pipes
Work is also being undertaken into predicting the effect of energy leakage from a buried pipe into the surrounding material, such as sand or soil. Similar finite element based techniques are being used to analyse the propagation of each mode and to compute the scattering from defects.
This permits the computation of important properties such as modal attenuation in buried pipes; see for example the effect of the surrounding material, as well as a coating, on the propagation of a Torsional (shear) family of modes.
This data enables the LRUT user to understand the effects of the surrounding medium so that they may identify the limitations of the technique for buried systems. However, this information is rather limited and it is difficult to use this data in the development of new and improved techniques. Therefore, we are now developing computational models that will predict the scattering from defects in buried pipes, as this provides a more complete model of the problem.
To date our models are capable of predicting scattering from an axisymmetric defect using T(0,1). This work is currently being extended to non-axisymmetric defects pipes.