EV Cooling Engineering Workbench

Config JSON Drive Cycle CSV Measured Log CSV Raw Logger CSV

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Dataset

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Scenario Manager

Drive-Cycle Preview

Power Speed

Engineering Plot

Component Table

System State

Sensitivity and Comparison

Calibration Check

Uncertainty Range

Ambient ± deg C Radiator UA ± % Flow ± % Efficiency ± points

Logger Import

Data Quality

Hydraulic Sizing

Hose length m Hose ID mm Minor K total Component Δp coeff Pump shutoff psi Pump free flow L/min

Δp ≈ f_D(L/D)(ρv²/2) + K(ρv²/2) + aQ²

This is a first sizing estimate using water-like density/viscosity. The pump operating point is the intersection of loop pressure drop and a simple linear pump curve.

Pump Curve

Branch Flow Split

Engineering Checklist

Coolant type checked against event rules Leak paths and fittings reviewed Pump/fan LV current budget checked Coolant, motor, inverter sensors logged Radiator bench-test plan created Dyno/track validation plan created

Radiator UA Fit

Engineering Templates

Model Equations

1. Component Heat Generation

Q̇_loss,i = |P_cycle · f_i| · (1 − η_i)

Vehicle power is distributed to each cooled component using its power fraction. Efficiency converts the non-useful portion into heat.

Q̇_loss,i: heat generated by component i.
P_cycle: drive-cycle power at the current time step.
f_i: fraction of total power assigned to component i.
η_i: efficiency of component i.

2. Component Temperature

C_i · dT_i/dt = Q̇_loss,i − UA_i · (T_i − T_c)

Thermal mass slows temperature rise. Component-to-coolant conductance controls how strongly heat moves into the coolant loop.

C_i: thermal capacitance of component i.
T_i: component temperature.
UA_i: component-to-coolant thermal conductance.
T_c: coolant temperature.

3. Coolant Energy Balance

C_c · dT_c/dt = Σ[UA_i · (T_i − T_c)] − Q̇_rad

The coolant lump collects component heat and rejects heat through the radiator.

C_c: coolant thermal capacitance.
Σ[UA_i(T_i − T_c)]: total heat transferred from components into coolant.
Q̇_rad: heat rejected by the radiator.

4. Radiator Rejection

Q̇_rad = UA_rad · F_ṁ · F_air · max(T_c − T_amb, 0)

Radiator effectiveness scales with coolant flow and air speed. Fan duty adds equivalent air speed at low vehicle speed.

UA_rad: radiator conductance at reference flow and air speed.
F_ṁ: correction factor for coolant flow rate.
F_air: correction factor for air speed through the radiator.
T_amb: ambient air temperature.

5. Pump and Fan Control

u = clamp((T_c − T_on) / (T_full − T_on), 0, 1)

Pump flow and fan power ramp linearly between on and full temperature setpoints.

u: pump or fan duty command from 0 to 1.
T_on: coolant temperature where the device starts ramping.
T_full: coolant temperature where the device reaches full command.
clamp: limits the command between 0 and 1.

6. Numerical Method

T_k+1 = T_k + Δt · (dT/dt)_k

The model uses explicit time stepping. It is a lumped-parameter model for design studies, not CFD or final validation.

T_k: temperature at the current time step.
T_k+1: temperature at the next time step.
Δt: simulation time step.
(dT/dt)_k: temperature rate of change evaluated at the current step.

Symbol Legend

Symbol	Meaning	Typical Unit
Q̇_loss,i	Heat generated by component i from inefficiency	W
P_cycle	Drive-cycle power at the current time step	W or kW
f_i	Fraction of drive-cycle power assigned to component i	−
η_i	Efficiency of component i	−
C_i	Thermal capacitance of component i	J/K
C_c	Coolant thermal capacitance, m_c c_p,c	J/K
T_i	Temperature of component i	°C
T_c	Coolant temperature	°C
T_amb	Ambient air temperature	°C
UA_i	Component-to-coolant conductance	W/K
UA_rad	Radiator conductance at reference conditions	W/K
F_ṁ	Coolant-flow correction factor	−
F_air	Airflow correction factor	−
Q̇_rad	Heat rejected by the radiator	W
u	Pump or fan duty command	0–1
Δt	Simulation time step	s