Contraste numérico-experimental de un modelo matemático que simula el movimiento del flujo en condiciones de aguas someras incluyendo las pérdidas de energía

In  this  paper,  a  comparison  between  the  results  obtained  in  laboratory  experiments  and  those  calculated  by  a numerical  simulation  of  shallow  water  equations  in  an  open  channel  is  performed,  considering  the  energy  losses that  occur  as  it  passes  through  a  local  narrowing  of  the  cross  section.  The mathematical model that simulates this physical phenomenon is governed by a partial differential equations system whose solution provides the water depth and the flow rate per unit of width, which is related to the velocity of the water. Such movement is controlled primarily  by  the  force  of  gravity,  being  fundamental  the  relationship  between  it  and  the  inertial  forces.  In the present study we have also taken into account energy losses caused by friction of the water with the contours and local losses caused by obstacles or changes in the width of the channel. A numerical scheme based on a high-order finite  volume  method  has  been  used  for  obtaining  the  solutions  of  such  model.  Two type of laboratory tests have been simulated.  The   first  type  represents  a  slow  transition  regime,  upstream  and  downstream  of  a  narrowing  in the channel. The second type represents a subcritical flow upstream, a narrowing that works as a control (regime change) and a downstream supercritical flow. Numerical-experimental comparison demonstrates the importance of adequately modeling of the different physical phenomena involved in the process, and the proper imposition of the boundary conditions of the problem