Periodic oscillations in a horizontal single boiling channel with thermal wall capacity

The dynamic behavior of a horizontal boiling channel with a surge tank is investigated through nonlinear analysis. The model involves a surge tank that is subject to inlet mass flow rate and a constitutive model containing a cubic nonlinearity is used to describe the outlet pressure-flow rate relation of the downstream boiling regime. The model also includes boiling heat transfer process and incorporates the effect of the wall thermal capacity which allows the temperature and heat transfer coefficient of the heater wall to vary with time. Within certain operating regimes, the model exhibits self-excited periodic oscillations, which can be identified with pressure-drop oscillations. In this study, these oscillations are described as relaxation oscillation and the qualitative features of the response can be understood in terms of the underlying model. Finally, the present model is compared with the experimental data available in literature to investigate that transient effects of temperature heater walls, pressure, and mass flow rate. (C) 2001 Elsevier Science Inc. All rights reserved.