Please use this identifier to cite or link to this item:
Title: Unsteady ice jam processes
Authors: Iowa Institute of Hydraulic Research
Zufelt, Jon E.
Ettema, R.
Keywords: Ice jams
Laboratory experiments
Unsteady processes
Ice mechanics
Frazil ice
River ice
Lake ice
Publisher: Cold Regions Research and Engineering Laboratory (U.S.)
Engineer Research and Development Center (U.S.)
Series/Report no.: CRREL report ; 97-7.
Description: CRREL Report
Abstract: Ice jams cause flooding in northern temperate-climate areas, usually forming rapidly, often with little warning, constricting water flow and elevating water levels. Consequently, jam formation comprises highly unsteady processes: drifting ice pieces are brought to rest, accumulated ice shoves and thickens, and initial water depths and velocities change. Those processes are even more unsteady when a jam collapses. Prior simulations of ice jams, however, treat them as simply stationary, uniformly thick accumulations of ice pieces. No account is taken of the impact forces exerted by moving ice, an estimation that is further complicated by the need to couple equations describing water flow and ice movement. Under the dynamic conditions attendant to jam formation, water flow and ice movement interactively influence each other. This report evaluates the importance of ice momentum on ice jam thickness and thickness distribution using experiments conducted with laboratory flumes and a numerical model in which the equations of motion for one-dimensional flow of water and ice are solved as fully coupled. In this regard, the model is unique, enabling simulation of the important unsteady interactions of water and ice, and determination of their effects on jam thickness. Ice momentum should be taken into account for most jams because it leads to significantly thicker jams and affects the thickness profile. A useful dimensionless parameter is identified for generalizing this finding.
Rights: Approved for public release; distribution is unlimited.
Appears in Collections:CRREL Report

Files in This Item:
File Description SizeFormat 
CR-97-7.pdf2.23 MBAdobe PDFThumbnail