Turbo Physics Grade 12 Pdf Page

But his measured 135°C meant . The compressor efficiency (η_c) = (T₂_ideal – T₁)/(T₂_actual – T₁) = (78-25)/(135-25) = 53/110 ≈ 48%. The rest of the work became heat due to friction and turbulence. Chapter 4: The Density Battle Kael connected the compressor outlet to a small engine cylinder. More air pressure meant more oxygen molecules per volume—but the heat reduced density. Using the ideal gas law rearranged: ρ = P / (R_specific × T)

Kael calculated: Using (η_t = (T₁ - T₂_actual)/(T₁ - T₂_ideal)), he found that 68% of the exhaust’s enthalpy (h = u + Pv) converted into shaft work. The rest became entropy—random molecular motion—which heated the turbine housing. turbo physics grade 12 pdf

To reduce lag, Kael lightened the turbine wheel (lower I) and designed a smaller A/R (area/radius) turbine housing—which increased exhaust velocity but reduced top-end flow. At full throttle, boost climbed past 2.2 atm. The engine detonated. Dr. Vane pointed to a small actuator: the wastegate. It diverted exhaust around the turbine when boost exceeded a setpoint. But his measured 135°C meant

At 1.8 atm and 135°C (408 K): ρ = (1.8 × 101325 Pa) / (287 J/kg·K × 408 K) ρ ≈ 182385 / 117096 ≈ 1.56 kg/m³ Chapter 4: The Density Battle Kael connected the