🏎️ Turbocharger Engine Match & Surge Margin Sizer

Calculate turbocharger turbine-compressor energy balance, compressor pressure ratio PR, engine airflow, turbine exhaust backpressure, surge margin, and shaft RPM.

⚡ Fortran 90 Engine Double Precision (IEEE 754) ✓ ISO / ASME Validated

Turbocharger Engine Match & Surge Margin Sizer

Turbomachinery

📊 Solver Telemetry ● ACTIVE

👁️ Views 19

⚡ Solves 14

💾 Downloads 300 📦 Fortran Code 5.2 KB

📅 Released Jun 2026

⏱️ Latency < 1 ms

🌀 Compressor Performance Map, Surge Line & Engine Match

Real-time visual simulation: Operating engine load point on PR vs corrected mass flow map

📝 Configuration & Presets

🏎️ 2.0L Gasoline Sports 🚛 12.8L Truck Turbo Diesel 🏁 2.5L Motorsport High-Boost ⚓ 6.6L Marine Aux Genset

🚗 Engine Displacement & Speed

Displacement V_d [Liters]:

Engine RPM [rpm]:

🎯 Target Boost & Temperatures

Boost Pressure [bar gauge]:

Manifold Temp [°C]:

Exhaust Temp T_exh [°C]:

⚙️ Efficiencies & Volumetric Filling

Volumetric Eff. η_vol:

Compressor Eff. η_c:

Turbocharger Matching Formulation:
• Airflow: ṁ_air = [V_d·(N/120)·η_vol·P_man] / (R·T_man) [kg/s]
• Compressor Power: P_comp = [ṁ·c_p·T₁ / η_c] · [PR_c^(γ−1)/γ − 1] [kW]
• Shaft Balance: P_turb · η_mech = P_comp
• Surge Margin: SM = (ṁ_corr − ṁ_surge) / ṁ_corr ≥ 15%.

📊 Performance Results

📊 Output Summary
💾 Fortran Source

Compressor Absorbed Power Demand

101.8 kW

Compressor PR: 3.27 | Turbo Speed: 126446 rpm

CHOKE / HIGH FLOW REGIME

Compressor Surge Margin 45.0% >15% SAE J1826 safe

Engine Airflow (ṁ_air) 2347 kg/h 0.652 kg/s (86.2 lb/min)

Turbine Expansion Ratio (PR_t) 2.38 Backpressure: 1.40 bar g

Turbo Shaft Speed 126446 rpm Exhaust T = 650 °C

📈 Compressor Power P (kW) vs Boost Pressure (bar g)

📊 Engine Airflow (kg/h) vs Engine Speed (rpm)

=================================================================
 THERMOFLUIDCALC — TURBOCHARGER ENGINE MATCH REPORT
=================================================================
Case Title                 : 12.8L Heavy-Duty Commercial Truck Turbo Diesel
Engine Specification       : 12.8L Displacement, N = 1800 rpm, Boost = 2.20 bar g
Thermal State              : Tman = 40.0 C, Texh = 650.0 C, eta_vol = 0.95
-----------------------------------------------------------------
COMPRESSOR POWER DEMAND    : 101.77 kW
Engine Airflow Rate        : 0.652 kg/s (2347.1 kg/h)
Compressor / Turbine PR    : PR_c = 3.27 / PR_t = 2.38
Turbine Exhaust Backpress. : 1.40 bar gauge
Estimated Turbo Shaft Speed: 126446 rpm
Surge Margin Compliance    : 45.0% (CHOKE / HIGH FLOW REGIME)
=================================================================

📘 Calculation Methodology & Turbocharging Standards

Turbocharger Power Match & Shaft Balance

The turbine extracts enthalpy from pulsating engine exhaust gases to drive the compressor wheel through a shared shaft with bearing mechanical losses: $P_{comp} = P_{turb} \cdot \eta_{mech}$.

Surge Margin & Choke Limits

Surge occurs at low mass flow and high boost where aerodynamic stall causes audible high-frequency flow reversal. A minimum 15% margin to the surge line is essential for reliable engine operation.

Key Engineering Assumptions

SAE J1826 gas stand compressor & turbine mapping.
4-stroke IC engine volumetric filling formulation.
Widely used in automotive powertrain engineering, diesel truck sizing, and marine propulsion.

ThermoFluidCalc Engineering Report