Comparison of Boeing 737-800 with Known and Estimated Mass Properties

This example compares the flight of Boeing 737-800 for a 3 h 15 min flight with its known mass properties (mass, inertia tensor and center of mass location) and mass properties that are estimated by using the weight estimation method found in the Aircraft library. The weight estimation method is presented in detail in reference [1]. Both aircraft are given the same reference trajectory.

The control panel for the aircraft design variables allows exploring how the adjustments in the design variables that are used to estimate the mass properties of an aircraft affect the performance of the Boeing 737-800. Additionally, the control panel lets the user adjust the amount of fuel carried onboard and resize the engines.

The first default plot shows the plots of interest when comparing the two variants of Boeing 737-800. With the estimated mass properties, the aircraft becomes slightly lighter than the known total mass of Boeing 737-800, thus resulting in smaller throttle demand and smaller fuel consumption.

The second default plot, on the other hand, shows how the aircraft fulfills the set constraints on the load factor and dynamic pressure during the flight. The values of the constraints are design variables in the weight estimation method used and thereby will also affect the estimated mass properties, as can be seen by adjusting their values in the control panel.

[1]  Erä-Esko, N. (2022). Development and Use of System Modeler 6DOF Flight Mechanics Model in Aircraft Conceptual Design. Available at: modelica://Aircraft/Resources/Documents/EraeEskoThesis.pdf.