Cylinder Pressure Analysis

catoolRT includes industry leading capabilities for analysing measured cylinder presssure. These allow the user to understand what is occuring inside the combustion chamber of the engine. This understanding can be used in research, engine design and development and powertrain control system calibration.

Some of the advanced analysis includes:

• Determination of maximum cylinder pressure and location
• Calculation of burn angles and rate
• Estimation of trapped charge
• Calculation of indicated torque, power and Mean Effective Pressure
• Comprehensive analysis of knock for onset and intensity
• Heat release analysis

Full list of cylinder pressure analysis channels:

• Absolute Cylinder Pressure Offset - POFF
• Start of Combustion - SOC
• Thermodynamic Loss Angle - TLA
• Mass Fraction Burned
  • Crank angle curve - MFB
  • Burn Angles - MFB01, MFB02, MFB05, MFB10, MFB20, MFB25, MFB50, MFB75, MFB80, MFB90, MFB95, MFB98, MFB99
  • Burn Durations - B0002, B0005, B0010, B0090, B0290, B0590, B1090
  • Maximum Burn Rate and crank angle - MXBRN, AMXBRN
• Centre of Gravity of burn - COG
• Load Calculation¹
  • Delta pressure during compression before combustion - DELTA_P
  • Trapped mass estimation - T_MASS
  • Normalised load from trapped mass estimation - LOAD
• Estimated End of Combustion - EEOC
• Indicated Mean Effective Pressures
  • Net MEP - NMEP
  • Gross MEP - GMEP
  • Lower Pumping MEP - LPMEP
  • Upper Pumping MEP - UPMEP
• Indicated Torque/Power
  • Indicated Power - INDPWR
  • Indicated Torque - TQIND
  • Indicated Torque (lb.ft) - TQLBFT
  • Net Indicated Torque - TQINDN
  • Crank angle indicated torque - TQANG, TQANGSUM
• Pressure Ratio
  • Pressure Ratio - PR
  • Pressure Ratio Fraction - PRF
  • Difference Pressure - DP
  • Crank Angle of 10bar Difference Pressure - DP10_
  • Dilution Parameter - DILPAR
  • Pressure Ratio Management - PRM10_, PRM25_
• Knock Analysis
  • Knock Factor - KF
  • Knock Integral - KNKINT
  • Checkel & Dale Knock Intensity and peak crank angle - CDKNK, ACDKNK
  • Knock Onset Angle - AKO
  • Knock Onset Unburnt Mass Faction Burned - KOUMFB
  • Peak Knocking Pressure and crank angle - KNKMAX, AKNKMX
  • Crank angle knocking pressure - KNKP
• Heat Release
  • Maximum heat release rate and crank angle - QRTMX, AQRTMX
  • Total heat release - QMAX
  • Crank angle gross heat release rate - GHR
  • Crank angle heat transfer coefficient - H
  • Crank angle net heat release rate - NHR
• Mean Gas Temperature
  • Max mean gas temperature and crank angle - MXT, ATMAX
  • Crank angle mean gas temperature - MGTEMP
• Cylinder Pressure
  • Maximum pressure and crank angle - PMAX, APMAX
  • Maximum pressure around intake valve opening and crank angle - PIVCMAX, APIVCMAX
  • Minimum pressure and crank angle - PMIN, APMIN
  • Minimum pressure around exhaust valve closing and crank angle - PEVCMIN, APEVCMIN
  • Crank angle smoothed pressure trace - PRAVG
  • Crank angle polynomial fit around TDC - POLYFIT
• Cylinder Pressure Rise Rate
  • Maximum pressure rise rate and crank angle - RPMAX, ARPMX
  • Crank angle pressure rise rate - PRR
• Polytropic Indices
  • Compression polytropic index - NCOMP
  • Expansion polytropic index - NEXP
  • Crank angle polytropic index - POLY
• Valve Timing
  • Estimated Exhaust Value Opening - EEVO
  • Estimated Inlet Valve Opening - EIVO
• Ratio of Specific Heats - GAMMA
• Wiebe parameters
  • Wiebe a parameter - WIEBEA
  • Wiebe m parameter - WIEBEM
  • Crank angle Wiebe MFB curve - WIEBE
• Motored Cylinder Pressure - MOTPR

References:
1. Worm, J., "An Evaluation of Several Methods for Calculating Transient Trapped Air Mass with Emphasis on the "Delta P" Approach," SAE Technical Paper 2005-01-0990, 2005