Coolant Flow Rate Calculator

Calculate required coolant flow rate based on engine heat rejection, temperature rise, and coolant properties.

Input Parameters

Results

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Required Flow Rate
GPM
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Flow Velocity
ft/s
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Heat Transfer Rate
kW
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Flow Regime
Note: Typical engine coolant flow: 20-40 GPM. Coolant velocity above 4 ft/s ensures turbulent flow for heat transfer. 50/50 ethylene glycol protects to -34°F.

Reference

Flow (lb/hr) = Q_BTU / (Cp × ΔT) Flow (GPM) = Flow_lb / (ρ × 60) Cp 50/50 EG = 0.82 BTU/lb·°F Velocity = Flow / Pipe Area Turbulent flow (>4 ft/s) needed for good cooling