This simulator models an inline two-stage booster pump train — first booster pump, interstage spool, second booster pump and three pressure stations — showing how one common flow passes sequentially through both stages, with each active stage adding its own head rise while the interstage pipe subtracts a friction loss from the combined total.
• A real-time 3D cutaway workbench (first booster pump/stage A, interstage spool and loss section, second booster pump/stage B, inlet/interstage/outlet pressure gauges, ideal stage bypasses and nonreturn paths, and common discharge line/load boundary) with home view, focus-selected-part, show full enclosure, exploded view, auto-rotate, expand and hide-labels scene tools. • A dedicated 'Combined pump and system curves' chart showing the summed stage curve against the system curve. • Experiment controls: Pump A speed, Pump B speed, Pump A enabled and Pump B enabled checkboxes, system static head, common system resistance and interstage pipe resistance sliders, plus pause/resume, single-step and 1 s-step buttons, four playback speeds, and dedicated 'Bypass pump B' / 'Enable pump B' actions. • A Curves & measurements analysis tab with two further live charts (stage A head, stage B head and net train head; common train flow), the underlying per-stage and combined equations, and snapshot readouts (common flow, stage A/B added head, interstage loss, net train head, after-stage-A pressure, net discharge pressure, estimated total shaft power, stage A/B bypass-active state). • An Experiments tab with four guided fixtures (two active stages, second stage bypassed, unequal stage speed, large interstage loss) and a Model verification bench with a timestamped event log and copyable trial report. • A Learn & assess tab with four guided lessons, a knowledge-check quiz with reset, and a written model-scope statement linking to a KSB pump-selection reference.
Unlike parallel operation, a series booster train passes the same volume flow sequentially through both stages: Qstage A path = Qstage B path = Qdelivery. Each active stage adds its own head rise at that shared flow, Hi(Q) = max[0, 40(ni/1800)² − 0.006Q²], and the net train head is the sum of both stage contributions minus the interstage pipe loss: Htrain = HA(Q) + HB(Q) − Klink·Q². This lets a two-stage train reach higher combined head at a given flow than either stage alone — but it still changes the operating flow only by moving up the same fixed system curve, not by adding flow the way parallel pumps do.
If a stage is switched off, or its computed head at the solved flow would be zero or negative, the model routes flow around it through an explicit, ideal zero-loss bypass rather than forcing flow frictionlessly through a stopped impeller or blocking the train entirely. The second-stage-bypassed and unequal-stage-speed experiments both show this bypass activating, which is a deliberate schematic simplification rather than a literal mechanical bypass valve model.
This is a steady synthetic-curve model with equal-elevation pressure stations and constant density; no reverse torque or blocked-stopped-pump condition is simulated, and the train includes a delivery nonreturn boundary. No casing pressure rating, seal limit, NPSH or water-hammer analysis is included — shaft power assumes a fixed 75% efficiency on positive-head stages only.
Head rises add at one common flow — the same volume flow passes through both stages sequentially, and each active stage contributes its own head increase at that shared flow. This differs from parallel operation, where flows (not heads) add at a common header pressure.
No — series staging is about reaching higher combined head at a given flow, not increasing flow directly. The actual delivered flow still depends on where the summed stage-head curve intersects the fixed system-resistance curve, so flow typically increases only modestly even though head capability rises substantially.
The model routes the common flow around it through an ideal, zero-loss bypass rather than forcing flow through a stalled impeller or blocking the train. Only the remaining active stage(s) contribute head in that condition, as shown in the second-stage-bypassed experiment.
Yes — the interstage spool between stages introduces its own quadratic friction loss, which is subtracted from the sum of both stages' head rises to give the net train head. A larger interstage resistance leaves less usable head at the same flow, as shown in the large-interstage-loss experiment.