EFPLAB1: * Borda-Carnot Expansion
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Borda-Carnot Expansion Flow Animation

A flowing fluid is unable to follow a sudden expansion of the cross-section. This leads the flow to separate from the wall. Thus forming a jet, which widens continuously over a distance that depends on the geometry until the flow reattaches again on the larger cross-section. For the Borda-Carnot expansion under consideration, the flow reattaches after 300 mm. Between the widening of the cross-section and the reattachment of the flow, an eddy water area with intense vortices is formed.

The animation illustrates the flow through the Borda-Carnot expansion for the respective operating point. The flow velocity of the water (including velocity vectors at the inlet and outlet) and the vortex formation in the eddy water are animated. In addition, the geometric dimensions and measuring positions of the pressure measurement are visible. Length and width of the animation are not scaled uniformly.

Variable:

Formula:

Formula with numeric values:

Result:

Pressure rise

(Borda) $p}_{2}-{p}_{1$

(Borda) $p}_{2}-{p}_{1$

$\rho \cdot {v}_{1}^{2}\cdot \frac{{A}_{1}}{{A}_{2}}\cdot (\frac{{A}_{1}}{{A}_{2}}-1)$

$998\text{}\frac{\mathrm{k}\mathrm{g}}{{\mathrm{m}}^{3}}\cdot {\left(5\frac{\mathrm{m}}{\mathrm{s}}\right)}^{2}\cdot \frac{\mathrm{}\text{}{\mathrm{m}}^{2}}{3\text{}{\mathrm{m}}^{2}}\cdot (\frac{2\text{}{\mathrm{m}}^{2}}{3\text{}{\mathrm{m}}^{2}}-1)$

$10\text{}\mathrm{P}\mathrm{a}$

Pressure loss

(Borda)

$\mathrm{\Delta}{p}_{v}$

(Borda)

$\mathrm{\Delta}{p}_{v}$

$\rho \cdot \frac{{v}_{1}^{2}}{2}\cdot {(\frac{{A}_{1}}{{A}_{2}}-1)}^{2}$

$998\text{}\frac{\mathrm{k}\mathrm{g}}{{\mathrm{m}}^{3}}\cdot \frac{{\left(5\text{}\frac{\mathrm{m}}{\mathrm{s}}\right)}^{2}}{2}\cdot \mathrm{}$

$10\text{}\mathrm{P}\mathrm{a}$