HY8:Straight Drop Structure: Difference between revisions

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The input variables required for this calculation is the following:
The input variables required for this calculation is the following:


Drop Height -- The vertical drop height from structure crest to channel bottom. In the final design, the drop height to the basin bottom is given. The difference between the two is the amount the basin is suppressed below the channel bottom.
Drop Height — The vertical drop height from structure crest to channel bottom. In the final design, the drop height to the basin bottom is given. The difference between the two is the amount the basin is suppressed below the channel bottom.


New Slope   -- The slope that will exist on the channel once the drop structures are in place (the new slope must be subcritical).
New Slope — The slope that will exist on the channel once the drop structures are in place (the new slope must be subcritical).




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Variables from the figure
Variables from the figure


* q -- Design Discharge  
* q — Design Discharge  
* y<sub>c</sub> -- Critical depth
* y<sub>c</sub> &mdash; Critical depth
* h<sub>0</sub> -- Drop from crest to stilling basin floor
* h<sub>0</sub> &mdash; Drop from crest to stilling basin floor
* y<sub>1</sub> -- Pool depth under the nappe
* y<sub>1</sub> &mdash; Pool depth under the nappe
* y<sub>2</sub> -- Depth of flow at the tow of the nappe or the beginning of the hydraulic jump
* y<sub>2</sub> &mdash; Depth of flow at the tow of the nappe or the beginning of the hydraulic jump
* y<sub>3</sub> -- Tailwater depth sequent to y2
* y<sub>3</sub> &mdash; Tailwater depth sequent to y2
* L<sub>1</sub> -- Distance from the headwall to the point where the surface of the upper nappe strikes the stilling basin floor
* L<sub>1</sub> &mdash; Distance from the headwall to the point where the surface of the upper nappe strikes the stilling basin floor
* L<sub>2</sub> -- Distance from the upstream face of the floor blocks to the end of the stilling basin
* L<sub>2</sub> &mdash; Distance from the upstream face of the floor blocks to the end of the stilling basin


[[Image:HY8image21.jpg]]
[[Image:HY8image21.jpg]]
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Variables from the figure
Variables from the figure


* y<sub>c</sub> -- Critical depth
* y<sub>c</sub> &mdash; Critical depth
* h<sub>0</sub> -- Drop from crest to stilling basin floor
* h<sub>0</sub> &mdash; Drop from crest to stilling basin floor
* h -- Vertical drop between the approach and tailwater channels
* h &mdash; Vertical drop between the approach and tailwater channels
* y<sub>1</sub> -- Pool depth under the nappe
* y<sub>1</sub> &mdash; Pool depth under the nappe
* y<sub>2</sub> -- Depth of flow at the tow of the nappe or the beginning of the hydraulic jump
* y<sub>2</sub> &mdash; Depth of flow at the tow of the nappe or the beginning of the hydraulic jump
* y<sub>3</sub> -- Tailwater depth sequent to y2
* y<sub>3</sub> &mdash; Tailwater depth sequent to y2
* L<sub>1</sub> -- Distance from the headwall to the point where the surface of the upper nappe strikes the stilling basin floor
* L<sub>1</sub> &mdash; Distance from the headwall to the point where the surface of the upper nappe strikes the stilling basin floor
* L<sub>2</sub> -- Distance from the upstream face of the floor blocks to the end of the stilling basin
* L<sub>2</sub> &mdash; Distance from the upstream face of the floor blocks to the end of the stilling basin
* L<sub>3</sub> -- distance from the upstream face of the floor blocks to the end of the stilling basin
* L<sub>3</sub> &mdash; distance from the upstream face of the floor blocks to the end of the stilling basin
* L<sub>B</sub> -- Stilling basin length
* L<sub>B</sub> &mdash; Stilling basin length




{{HY8Main}}
{{HY8Main}}

Revision as of 00:06, 10 January 2013

The input variables required for this calculation is the following:

Drop Height — The vertical drop height from structure crest to channel bottom. In the final design, the drop height to the basin bottom is given. The difference between the two is the amount the basin is suppressed below the channel bottom.

New Slope — The slope that will exist on the channel once the drop structures are in place (the new slope must be subcritical).


The following figures show straight drop structures.


HY8image20.jpg


Variables from the figure

  • q — Design Discharge
  • yc — Critical depth
  • h0 — Drop from crest to stilling basin floor
  • y1 — Pool depth under the nappe
  • y2 — Depth of flow at the tow of the nappe or the beginning of the hydraulic jump
  • y3 — Tailwater depth sequent to y2
  • L1 — Distance from the headwall to the point where the surface of the upper nappe strikes the stilling basin floor
  • L2 — Distance from the upstream face of the floor blocks to the end of the stilling basin

HY8image21.jpg

Variables from the figure

  • yc — Critical depth
  • h0 — Drop from crest to stilling basin floor
  • h — Vertical drop between the approach and tailwater channels
  • y1 — Pool depth under the nappe
  • y2 — Depth of flow at the tow of the nappe or the beginning of the hydraulic jump
  • y3 — Tailwater depth sequent to y2
  • L1 — Distance from the headwall to the point where the surface of the upper nappe strikes the stilling basin floor
  • L2 — Distance from the upstream face of the floor blocks to the end of the stilling basin
  • L3 — distance from the upstream face of the floor blocks to the end of the stilling basin
  • LB — Stilling basin length