**Introduction**

The data provided is from a high fidelity system level engine simulation
designed to simulate nominal and fault engine degradation over a series
of flights. The flights are full flight recording sampled at 1 Hz and
consists of 30 engine and flight condition parameters. Each flight
contains 7 unique flight conditions for an approximately 90 min flight
including ascent to cruise at 35K ft and descent back to sea level. The
simulated data was created with a Matlab Simulink tool called C-MAPSS.

**Background**

C-MAPSS stands for 'Commercial Modular Aero-Propulsion System
Simulation' and it is a tool for the simulation of a realistic large
commercial turbofan engine. The code is a combination of Matlab (The
MathWorks, Inc.) and Simulink (The MathWorks, Inc.) with a number of
graphical user interface (GUI) screens that allow point-and-click
operation and with editable fields that allow the user to enter specific
values of his/her own choice. In addition to the engine model (called
the 90K because it is produces about 90,000 lb of thrust), the package
includes an atmospheric model capable of operation at (i) altitudes from
sea level to 40,000 ft, (ii) Mach numbers from 0 to 0.90, and (iii)
sea-level temperatures from -60 to 103 °F. The package also includes a
power-management system that allows the engine to be operated over a
wide range of thrust levels throughout the full range of flight
conditions.

A comprehensive control system is included that consists of (i) a
fan-speed controller for which the user specifies the throttle-resolver
angle (TRA), (ii) three high-limit regulators that prevent the engine
from exceeding its design limits for core speed, engine-pressure ratio,
and HPT exit temperature, (iii) a fourth limit regulator that prevents
the static pressure at the HPC exit from going too low, (iv)
acceleration and deceleration limiters for the core speed, and (v) a
comprehensive logic structure that integrates these control-system
components in a manner similar to that used in real engine controllers
such that integrator-windup problems are avoided. Furthermore, all of
the gains for the fan-speed controller and the four limit regulators are
scheduled such that the controller and regulators perform as intended
over the full range of flight conditions and power levels.

The inputs are fuel flow and a set of 13 health-parameter inputs that
allow the user to simulate the effects of faults and deterioration in
any of the engine's five rotating components (fan, LPC, HPC, HPT, and
LPT).

**Fault types**

-   Fan: inlet engine fan

-   LPC: Low pressure compressor

-   HPC: High pressure compressor

-   HPT: High pressure turbine

-   LPT: Low pressure turbine

**Simulation Setup**

The simulation was designed as follows: Each flight is a combination of
a series of flight conditions with a reasonable linear transition period
to allow the engine to change from one flight condition to the next. The
flight conditions are arranged to cover a typical ascent from sea level
to 35K ft and descent back down to sea level. 7 unique flight conditions
are used with a total of 14 total states for a 90 minute flight sampled
at 1 Hz. Each engine is given an exponentially degrading fuel flow and
efficiency profile that describes 300 flights. The engine is then
assigned 1 of the 5 possible faults (fan, LPC, HPC, HPT, and LPT). For
nominal runs the standard fuel flow and efficiency degradation profiles
are used. During fault runs the fault is set to randomly occur during
the first 60 flights. During that flight the fault is introduced at a
random time sample. The fault is manifested by increasing the fuel flow
and efficiency parameters degradation by 25% or 50% for the 2 fault
engines runs from the fault time point on till the end of the simulation
for the remaining flights. After a flight is simulated a snapshot of all
engine parameters are taken in the middle of cruise and used to
calculate the health parameter for the engine. If the health parameter
drops below 0 no further flights are simulated for that engine.

**Data**

There are 5 types of faults simulated. Each fault has 5 examples of
nominal engines and 2 examples of faulty engines, one at 25% increased
degradation and the other at 50%. Each engine directory will have a
series of flights **FlightXXX.csv** in csv format. The first row of each
flight will contain the engine flight condition parameters and the rows
represent time samples. Each engine directory will also contain
**Engine_Fuel_Effic.csv**, which is the engine fuel and efficiency
profile used as input for the simulator for all flights.
**EngineHealth.csv** contains the calculated engine health for each
flight based on the snapshot of the engine parameters at cruise. Finally
the **Simulation_Info.txt** contains a summary of the number of flights,
the fault type that was simulated, if it is nominal or not, and if not
what flight and time sample the fault was introduced.

**Parameter descriptions**

  --------------------- ------------------------------------- ------------
  Parameter Name        Description                           Units

                        **Flight Conditions**                 

  time                  Flight time                           sec

  alt                   Altitude                              ft

  MN                    Mach number                           pct

  TRA                   Throttle resolver angle               deg

  Wf                    Fuel flow                             pps

  Fn                    Net thrust                            lbf

                        **Health Indicators**                 

  SmHPC                 HPC stall margin                      \--

  SmLPC                 LPC stall margin                      \--

  SmFan                 Fan stall margin                      \--

                        **Measurement Temperatures**          

  T48                   Total temperature at HPT outlet       R

  T2                    Total temperature at fan inlet        R

  T24                   Total temperature at LPC outlet       R

  T30                   Total temperature at HPC outlet       R

  T50                   Total temperature at LPT outlet       R

                        **Pressure Measurements**             

  P2                    Pressure at fan inlet                 psia

  P15                   Total pressure in bypass-duct         psia

  P30                   Total pressure at HPC outlet          psia

                        **Other Measurements**                

  Nf                    Physical fan speed                    rpm

  Nc                    Physical core speed                   rpm

  epr                   Engine pressure ratio (P50/P2)        \--

  phi                   Ratio of fuel flow to Ps30            pps/psiu

  Ps30                  Static pressure at HPC outlet         psia

  NfR                   Corrected fan speed                   rpm

  NcR                   Corrected core speed                  rpm

  BPR                   Bypass ratio                          \--

  farB                  Burner fuel-air ratio                 \--

  htBleed               Bleed enthalpy                        \--

  PCNfRdmd              Percent corrected fan speed           pct

  W31                   HPT cooland bleed                     lbm/s

  W32                   HPT cooland bleed                     lbm/s
  --------------------- ------------------------------------- ------------