Public Domain Aeronautical Software (PDAS)  

The ARIES program analyzes aircraft brake performance during rollout. The program simulates a three degree of freedom rollout after nose gear touchdown. The amount of brake energy dissipated during landing determines the life expectancy of brake pads. ARIES incorporates brake pressure, actual flight data, crosswinds, and runway characteristics to calculate the following:

  1. brake energy used during rollout for up to four independent brake systems,
  2. time profiles of rollout distance, velocity, deceleration, and lateral runway position, and
  3. all aerodynamic moments on the vehicle.

ARIES can be adapted for modeling most landing aircraft during unpowered rollout. Optimum braking procedures can be developed with ARIES to minimize brake deterioration while staying within specified lengths of runway. ARIES has been used to evaluate several Shuttle Orbiter brake pad failures.

After the input of initial runway and landing conditions, ARIES utilizes three simulation models to evaluate the rollout at given time intervals. The brake force simulation requires tire and brake information along with actual flight data. The equations of motion allow force and moment balances to be calculated. The aerodynamic effects are computed, including lift, drag, axial and normal forces, and roll, pitch, and yaw moments. The various aerosurface effects are obtained from interpolation of the Rockwell Aero Sciences Group Design Data Book tables. The output is in both printed and plotted form. ARIES iterates the calculations until the computed forward velocity is below three knots. ( Rockwell International Corp. for NASA Marshall)

This program was released by NASA through COSMIC as program MSC-20816. The italicized text above is from the original NASA release to COSMIC. The source code is reasonably well documented and is rather interesting. However, the aero data is to be read from the Rockwell Data Book tables, and these are not included with the program. The telemetry data from the vehicle must be in the same format as that used in the NASA space shuttle program. Overall, I think this program is too tightly bound to Space Shuttle operations to be useful in its original format. If you were going to write a new brake performance program for your application, it would be nice to have this code for reference.

Public Domain Aeronautical Software (PDAS)