1 / 9

The NWS S i mp lified D am B rea k Model SMPDBK Model

The NWS S i mp lified D am B rea k Model SMPDBK Model. SMPDBK Model Description. The NWS SMPDBK model computes the dam break outflow from a simplified equation and routes the outflow base on curves generated with the NWS DAMBRK model. Flow depths are computed based on Manning’s equation.

onella
Download Presentation

The NWS S i mp lified D am B rea k Model SMPDBK Model

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The NWS Simplified Dam Break ModelSMPDBK Model

  2. SMPDBK Model Description The NWS SMPDBK model computes the dam break outflow from a simplified equation and routes the outflow base on curves generated with the NWS DAMBRK model. Flow depths are computed based on Manning’s equation.

  3. SMPDBK Limitations • Backwater effects ignored • No special effects included (e.g. bridges, dams, constrictions, etc.) • Error range: 0 - 10% Relative to NWS DAMBRK (when used within its limitations) • Rapid, easy, low cost, emergency situations

  4. SMPDBK Model PEAK OUTFLOW: Qo = Spillway Flow Br = Breach Width (avg.) tf = Time of Failure (hour) hd = Height of Dam As = Avg. Surface Area of Reservoir in Top Portion of Reservoir Qbmax corrected for tailwater submergence and dynamic effects

  5. SMPDBK Model FLOW DEPTH: Depths computed from Manning Eq. for a known discharge The slope (S) is dependent on the upstream and downstream reach: If both subcritical, use average slope; If both supercritical, use upstream slope; If upstream slope is supercritical & downstream slope is subcritical, hydraulic jump present – compute two depths; If upstream slope is subcritical & downstream slope is supercritical, use critical slope (Sc;

  6. SMPDBK Model ROUTED FLOW: Routing of peak discharge via empirically derived relationships (using DAMBRK model) as represented via dimensionless parameters Qp/Qbmax, X/Xc, V*, and Fr.

  7. SMPDBK Model

  8. SMPDBK Model Time to Peak (Tp): Manning Equation:

  9. SMPDBK Model Time to Flooding and Deflooding of Elevation hf:

More Related