Upskill / Space & drones / Compressors, turbines and combustors: aerodynamics, cooling and emissions
Compressors, turbines and combustors: aerodynamics, cooling and emissions
Inside the core of a turbofan: compressor stages, velocity triangles and stall margin, combustor stability and liner cooling, emissions and ICAO Annex 16 Volume II, turbine cooling, coatings and creep, and the secondary air system, worked through one illustrative engine design. Part 2 of the Propulsion engineering series.
By Aerospace Garage Desk · Managing it · 45 minutes · 24 narrated pages
What you will be able to do
✓ Use the Euler equation and velocity triangles to calculate compressor stage work, temperature rise and pressure ratio, and estimate a stage count.
✓ Read a compressor map, define stall margin, and build and audit a stall margin budget, including the role of variable stators, bleed and spool split.
✓ Explain combustor stability, liner film cooling and the rich-burn and lean-burn approaches, and calculate a combustor energy balance and air split.
✓ Explain how NOx, CO, unburned hydrocarbons and nvPM form, and calculate Dp/Foo over the ICAO Annex 16 Volume II landing and take-off cycle.
✓ Calculate the cooling effectiveness a turbine blade needs and explain the roles of film cooling, thermal barrier coatings, creep and single-crystal alloys.
✓ Describe the secondary air system and seals, and draw the lessons of an official investigation into a combustor can failure.
Course content
Session 1 · Compressor aerodynamics: stages and velocity triangles
1.1
What one compressor stage does · free preview
Velocity triangles in words
Why rear stages give less pressure ratio
Worked example: one stage, then the whole compressor
Session 2 · Surge, stall margin and operability
1.2
The compressor map: speed lines, surge line and operating line
Stall margin and what eats it
Variable stators, bleed valves and spools
Worked example: auditing a stall margin budget
Session 3 · Combustors: flame stability and liner cooling
1.3
What a combustor must do
Liner cooling: keeping the flame off the wall
Combustor architectures: cans, annular, rich and lean
Worked example: the combustor energy balance
Session 4 · Emissions and the ICAO standards
1.4
How NOx, CO, unburned hydrocarbons and particles form
ICAO Annex 16 Volume II: what is certified
Designing for low emissions: the trade-offs
Worked example: totting up the landing and take-off cycle
Session 5 · Turbines: cooling, coatings and creep
1.5
Turbine aerodynamics: big work from few stages
Blade cooling and thermal barrier coatings
Creep, fatigue and the materials that resist them
Worked example: how much cooling does the blade need?
Session 6 · Secondary air system, seals and the lessons of failure
1.6
The secondary air system: cooling, sealing and purging
Seals and clearances: the hidden efficiency
Where the Propulsion engineering series goes next
From the investigation file: the combustion can that failed, G-BGJL, Manchester 1985
Who this course is for
Propulsion and component engineers at engine makers, suppliers and design organisations working on compressors, combustors, turbines and secondary air systems
Powerplant engineers in operators, MROs and engine shops who judge hot-section findings, repairs, stall events and emissions data and want the engineering behind them
Environmental, certification and technical managers who need to read ICAO Annex 16 Volume II emissions figures and engine-design trade-offs with confidence
You need: Part 1 of the Propulsion engineering series (or equivalent cycle knowledge) and comfort with algebra and a calculator.
Upskill courses are for professional development and are not approved by any aviation authority. Learner Terms