Analysis of the Thrust Force on the Temperature-Control Curtain in a Large Stratified Reservoir

Abstract

A temperature-control curtain (TCC) is an effective facility to regulate the outflow temperature in reservoirs, and its safety and stability are of great concern. The pressure difference between the front and back of a TCC induces a thrust force on the TCC. Previous studies examined the effect of TCCs on the discharged temperature of reservoirs, but the force analysis of the TCC in a stratified reservoir has not been studied. Taking Sanbanxi Reservoir as a case study, this work explains the thrust force exerted on a TCC. A three-dimensional hydrodynamic and temperature model is built and validated using the physical model test and prototype observed data. Using a numerical simulation under typical scenarios, the pressure difference on the TCC is identified, and the regularity of the thrust force is estimated. The research results are as follows: (1) For a bottom TCC in a reservoir with strong thermal stratification, because of the temperature difference between the two sides of the TCC, the thrust force on the TCC consists of hydrostatic and hydrodynamic pressure differences, and both are in the downstream direction. Between the two parts, the proportion of the hydrodynamic pressure difference is much larger; (2) when the flow height decreases, the thrust force on the TCC rapidly increases. Both hydrostatic and hydrodynamic pressure differences increase, and the latter changes more rapidly; (3) when the thermal stratification becomes stronger, the hydrostatic pressure difference increases, the hydrodynamic pressure difference decreases, and the thrust force on the TCC decreases; (4) for a top TCC, the hydrostatic pressure difference points in the upstream direction. However, because of the giant hydrodynamic pressure difference, the thrust force on the top TCC is much greater than that on the bottom TCC. In addition, three TCC implementation schemes are proposed with a focus on engineering. This study quantitatively estimates the mechanism of thrust force on a TCC and provides a theoretical foundation for practical application.