Overview
The ability to run multiple types of analyses across different airframes over a range of user defined flight conditions is at the heart of the analyses capabilities of the j2 Universal Tool-Kit. Start with validation checks at known conditions with j2 Freedom before expanding the test cases our to look at the complete flight envelope and multiple configuration trims. These can be used to investigate VTOL technologies and transition between hover and forward flight. Use j2 Freedom and the response modelling capabilities to fly the aircraft through the complete flight test and certification program. When flight data is available, the j2 Flight plug-in enables a complete flight matching and envelope expansion capability.
When evaluating the Handling Qualities, j2 Classical can be used to establish the complete set of modes of motion characteristics, identifying the frequency and damping of oscillatory modes across the complete flight envelope and all phases of flight. The introduction and development of Automatic Flight Control Systems can be developed using the j2 Matlab Tool-Box. Find key performance characteristics with j2 Performance
Analysis
j2 Freedom
The j2 Freedom Plug-In is the j2 Universal Tool-Kit’s flight modelling engine. It is used to evaluate the static and dynamic behaviour of the aircraft to assess stability and performance. Cases can be set up to enable the user to review the whole aircraft aerodynamic characteristics, the dynamic derivatives, and the control surface contributions. Any scenario can be constructed for steady state, static and dynamic analysis.
j2 Freedom also provides a “virtual wind tunnel” capability where the model can be run through a series of wind tunnel type tests to calculate the total coefficients from the individual contributions.
Full flight test or certification programs can be run using j2 Freedom from the very beginning of the project, and across multiple options/configurations without the need to rebuild the model or analysis each time. This is done in conjunction with the j2Flight plug in.
Analysis
j2 Matlab Toolbox
the j2 Matlab Toolbox allows direct integration with Matlab/Simulink. A simple Simulink block provides access to any aircraft in the j2 Universal Database. No need to rebuild the complete aircraft in Simulink. Always work with the latest version. Build the Flight Control Systems around the open-loop aircraft model developed in j2 Builder. With the FCS defined, a complete system diagram can be loaded, using the easy to use GUI, into j2 Universal for analysis. All test cases and conditions already defined can be applied to the closed-loop solution using models integrated using the Matlab Toolbox.
Analysis
j2 Classical
Using j2 Classical, the user can investigate classical linear analysis. Linearize the aircraft about any initial condition or flight case and identify the state space solution. Using Eigenstructure Analysis, the aircraft modes of motion can be identified, along with all characteristics such as frequency, damping time to half amplitude etc. Results can easily be compared to standards and limitations to evaluate compliance. Using j2 Visualise also means that all graphs and charts can be templated and re-used as required.
Analysis
j2 Flight
j2 Flight provides the unique ability to review the flight test data and to identify the model corrections required. The plug-in provides Flight Path Reconstruction to identify all aircraft states and to remove noise and bias from the sensors. Re-Prediction allows the flight data to be "pushed" through the model for qualification and flight matching. Finally taking the Re-Prediction results, the user is able identify corrections required on the model. These corrections can automatically be added to an aircraft model and the analysis re-run.
Uniquely, the j2 Flight plug-in allows the user to place the model at the same point in space and time as the flying aircraft, thus removing a significant proportion of additional data processing and data correction steps.
Analysis
j2 Performance
j2 Performance adds an additional search capability for finding boundaries, max/min values, and cross-coupling of parameters to optimize the aircraft’s characteristics. Combine these analyses with the ultimate flexible trimming capability to investigate point performance characteristics such as stall speeds, rates of turn, rates of climb etc is a highly effective and insightful tool to have when planning flight test activities.
Analysis
j2 Active
j2 Active integrates the power of the j2 Universal Tool-Kit into your current design toolset. This provides another API for connecting external analyses directly into the system to ensure that everyone is working with a consistent aircraft model. Results from other analyses can be extracted and used for further work. This removes the continual duplication where each discipline creates their own model and performs their own trimming/initialisation routines.