Effects of stratification on multi-layered tsunami waves
In: Coastal Research Library. Springer: Cham. ISSN 2211-0577; e-ISSN 2211-0585, more
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| Authors | | Top |
- Imteaz, M.A.
- Mekanik, F.
- Ahsan, A.
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| Abstract |
Widely used tsunami warning systems are based on numerical simulations and consider a single layer system, i.e. it is considered that the whole depth of ocean water is having a single density, which is not a realistic approximation. In order to develop a generalized numerical model for multi-layered tsunami wave system, a three-layer system was developed earlier. Six governing equations, two for each layer were derived from Euler equations of motion and continuity for three layers, assuming long wave approximation, negligible friction and interfacial mixing. Developed governing equations were converted to a numerical model using staggered Leap-Frog scheme for the computations of water level and discharge in each layer in one-dimensional propagation. Developed numerical model results were earlier validated (through converting it to a pseudo two- layer model) with a two-layer model, which was rigorously verified by analytical solution. This paper presents effects of stratification on the amplification and water levels of tsunami waves. For the representation of the magnitude of stratification, a new dimensionless number named “stratification number” has been proposed. The model has been simulated for several combinations of layer densities. It is found that with the increase in stratification number magnitude of wave surface level as well as wave amplitude decrease. |
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