BUBTEX Venturi NanoBubble Reactor SIM
Heatmap slice and sampling plane follow this setting.
Throat velocity ≈ m/s • Pipe ID 10 cm → Throat ID 5.5 cm • Diffuser length 30 cm
Coverage sweet-spot score
— / 100
Averaged near-wall hits over textured length (Δx = 2 mm). Normalized to session rolling maximum.
Physics (lane model)
xpeak≈ cm at current velocity
Lane model (what these sliders do)
Axial peak location is set by:
$x_{\text{peak}} = x_{\text{throat exit}} + \text{Base peak} + (\text{Velocity shift})\,(V_{in}-2)$.
The lane is Gaussian along x with the selected axial $\sigma$, and radially concentrated near the wall with the selected radial $\sigma$.
The lane is Gaussian along x with the selected axial $\sigma$, and radially concentrated near the wall with the selected radial $\sigma$.
Current estimate: $x_{\text{peak}} \approx$ – cm downstream of the throat.
In lab work we will calibrate these sliders to photos/videos of the real lane, then revisit ring placement.
Shear & bulk breakup (qualitative)
Left Y: wall shear τw (Pa). Right Y: Hinze bulk breakup ceiling dmax (µm). Rings shaded.
Info & Help
Governing relations
Inline velocity by continuity: $U(x) = V_{in}\,\dfrac{A_{in}}{A(x)}$, with $A(x)=\pi r(x)^2$.
Reynolds: $\mathrm{Re}(x)=\dfrac{\rho U(x) D(x)}{\mu}$.
Friction factor (smooth): $f=64/\mathrm{Re}$ (laminar), $\;f\approx0.3164\,\mathrm{Re}^{-0.25}$ (turbulent).
Wall shear: $\tau_w(x)=\dfrac{f(x)}{8}\,\rho\,U(x)^2$.
Near-wall dissipation: $\varepsilon(x)\approx\dfrac{u_*^3}{\kappa y}$ with $u_* = \sqrt{\tau_w/\rho}$, $\kappa\approx0.41$.
Hinze ceiling: $d_{\max}(x)=C_H\left(\dfrac{\sigma}{\rho}\right)^{3/5}\,\varepsilon(x)^{-2/5}$ (plotted in µm).
Reynolds: $\mathrm{Re}(x)=\dfrac{\rho U(x) D(x)}{\mu}$.
Friction factor (smooth): $f=64/\mathrm{Re}$ (laminar), $\;f\approx0.3164\,\mathrm{Re}^{-0.25}$ (turbulent).
Wall shear: $\tau_w(x)=\dfrac{f(x)}{8}\,\rho\,U(x)^2$.
Near-wall dissipation: $\varepsilon(x)\approx\dfrac{u_*^3}{\kappa y}$ with $u_* = \sqrt{\tau_w/\rho}$, $\kappa\approx0.41$.
Hinze ceiling: $d_{\max}(x)=C_H\left(\dfrac{\sigma}{\rho}\right)^{3/5}\,\varepsilon(x)^{-2/5}$ (plotted in µm).
Sampling definitions
Slice slab thickness: about the slice plane (x).
Near-wall band: inward from the wall radius at that x.
These values are used by the slice count and the coverage score.
Near-wall band: inward from the wall radius at that x.
These values are used by the slice count and the coverage score.
Score normalization
Coverage sweet-spot score is normalized to the highest mean near-wall count observed in this session
(rolling maximum = –). Resetting normalization sets the baseline to 50.
Use scores to compare placements within the same session.
Geometry (cm)
Limitations (read before interpreting)
• No CFD; fields are analytic/empirical for speed.
• Friction factor assumes smooth pipe (Blasius); separation/roughness would shift τw.
• Hinze curve is a bulk breakup ceiling, not a nanobubble predictor.
• Nanobubble overlay is visual only (conversions of near-wall microbubbles inside ring zones).
• Scores are relative (normalized to session maxima); compare within a session.
• Friction factor assumes smooth pipe (Blasius); separation/roughness would shift τw.
• Hinze curve is a bulk breakup ceiling, not a nanobubble predictor.
• Nanobubble overlay is visual only (conversions of near-wall microbubbles inside ring zones).
• Scores are relative (normalized to session maxima); compare within a session.
How to use this in lab
Pre-lab: set geometry and inlet velocity; adjust lane sliders to match expected visuals; place rings for high coverage score with safe throat offset.
During lab: replicate settings; for each configuration click Save log; note ΔP / DO rise / D50 in lab sheet.
Post-lab: export CSV/XLSX; compare coverage & shear context with outcomes; recalibrate lane sliders if photos show the lane farther/narrower, then iterate placement.
During lab: replicate settings; for each configuration click Save log; note ΔP / DO rise / D50 in lab sheet.
Post-lab: export CSV/XLSX; compare coverage & shear context with outcomes; recalibrate lane sliders if photos show the lane farther/narrower, then iterate placement.
Session logging
0 logs in session
Nanobubbles are a qualitative overlay derived from near-wall microbubbles downstream of the rings.
