Avl Boost Tutorial Upd -

Click on a cylinder → Combustion tab. For SI engines at full load, select:

Do not use the old “Vibe 2-parameter” unless specifically required – the new model auto-calibrates from laminar flame speed correlations.

AVL Boost expects a specific subroutine interface. Navigate to your project directory and locate or create the user.f file. Below is a template for a custom burn rate model (a simple Gaussian function, as example): avl boost tutorial upd

      SUBROUTINE USER_CYLINDER(CA, X, DX, V, DV, P, DENS, T, 
     &                         MF, AF, ETAC, ETAS, QLHV, 
     &                         HR, BURN, PTHB, USER_PAR, 
     &                         N_UP, I_ERR, TEXT)
  IMPLICIT NONE
  REAL*8 CA, X, DX, V, DV, P, DENS, T, MF, AF, ETAC, ETAS
  REAL*8 QLHV, HR, BURN, PTHB, USER_PAR(*)
  INTEGER N_UP, I_ERR
  CHARACTER*80 TEXT
! Local variables for custom model
  REAL*8 CA_SOC, CA_DUR, SHAPE, CUM_BURN, PI
  PARAMETER (PI = 3.1415926535)
! --- Read user parameters from GUI ---
  ! USER_PAR(1) = Start of Combustion [deg CA]
  ! USER_PAR(2) = Combustion Duration [deg CA]
  ! USER_PAR(3) = Gaussian shape factor
  CA_SOC = USER_PAR(1)
  CA_DUR = USER_PAR(2)
  SHAPE  = USER_PAR(3)
! --- Gaussian Burn Rate Function ---
  ! Normalized burn rate = exp(-0.5 * ((CA - CA_SOC)/(CA_DUR/6))^2)
  IF (CA .LT. CA_SOC) THEN
      BURN = 0.0
  ELSE
      BURN = EXP(-0.5 * ((CA - CA_SOC) / (CA_DUR/6.0))**2)
      ! Normalize integral to 1.0 over combustion duration
      CUM_BURN = ...  (numerical integration simplified here)
  END IF
! Assign results 
  ! BURN = dMF/dcrank (mass fraction burned derivative)
  ! HR = Heat Release Rate [J/deg] = BURN * MF * QLHV
HR = BURN * MF * QLHV  ! [J/deg]
! Error handling
  I_ERR = 0
  TEXT = 'User model executed'
RETURN
  END

Key variables to know:

Maya used Boost in three places:

Using boost::optional made user-facing APIs safer; iterator_facade saved boilerplate for const/non-const iterators.

To export cylinder pressure to CSV for external plotting (Matlab/Python): Click on a cylinder → Combustion tab

# Inside AVL BOOST Python Console (Tools → Python Console)
import avl_boost_api as avl
case = avl.get_current_case()
pressure = case.get_element_result("Cylinder_1", "CylinderPressure")
pressure.to_csv("pressure_vs_ca.csv")

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To follow this tutorial, ensure your system meets:

Installation UPD tip: After installing the latest version, always run the AVL License Manager and verify that your license file includes BOOST_Core and BOOST_Opt features. Without _Opt, you cannot use the optimizer module. Do not use the old “Vibe 2-parameter” unless

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