Box culvert with 90 deg. bend at exist

[sujanshakya]

Hi, I am modeling 5 barrel box culvert and at the exist the stream bends 90 degree. How to handel exist loss at D/S cross section in HEC_RAS. What should be exist loss coefficient approximately to enter into the ' Set Internal Changes in WS and EG - K Loss ' in HEC_RAS

 

[gbam]

I would say that it depends on the shape of the 90^ bend. If abrupt then I would lose the vel. head, ie k=1 +/-. This can be evaluated externally. I do not believe that HECRAS can handle this.

 

[sujanshakya]

I did calculate the k-value for 90 degree channel bend based on the experimental data published by K-TRAN (Kansas DOT) and entered into Hec_Ras Internal Changes in WS and EG Editor. I guess, this takes into account for the loss due to 90 degree bend at the particular cross section. Thanks to K-TRAN for this experimental findings.