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Modeling of unsteady temperature distribution in rivers with thermal discharges
Author(s) -
Hills R. G.,
Viskanta R.
Publication year - 1976
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/wr012i004p00712
Subject(s) - thermal stratification , environmental science , stratification (seeds) , thermal , turbulence , mechanics , evaporation , channel (broadcasting) , dissipation , meteorology , atmospheric sciences , hydrology (agriculture) , materials science , geology , thermodynamics , geotechnical engineering , physics , seed dormancy , germination , botany , electrical engineering , dormancy , biology , engineering
Analysis is presented for predicting unsteady temperature distribution in a channel simulating a river. The effects of thermal discharges, meteorological conditions, solar and atmospheric radiation and channel parameters on the thermal structure of a river are analyzed and discussed by utilizing an analytical model for the unsteady three‐dimensional temperature distribution in the far field of a thermally stratified channel. The effects of thermal start‐up, discharge temperature level, discharge location, river flow velocity, and others are investigated. The results show that the greater the temperature excess above the ambient at the discharge, the greater downstream distance is needed to reach a fully mixed condition because of the suppressive effect of stratification on the turbulent mixing. The greater surface temperatures associated with thermally stratified flow result in increased heat dissipation and water evaporation from the surface.