j2 Rotary

High Fidelity Rotary Models

The j2 Universal Tool-Kit provides high fidelity rotary modelling capability through the j2 Rotary plug-in. This accurately delivers autorotation, expected ground effect efficiencies, and realistic translational lift ‘right out of the box’.

For the j2 Rotary plug-in, j2 Aircraft Dynamics has teamed up with Presagis to provide a significant advance in high fidelity rotary modelling. The use of the Blade Element Rotary Model (BERM), from HeliSIM, integrated into the j2 Universal Tool-Kit’s flight dynamics and modelling environment provides a unique and rapid rotary prototyping capability.

This means the model is able to simulate the complete operational envelope of the helicopter including stability in hover and tail rotor failures. Additional effects are accurately modelled including downwash and downwash ingestion, Upwash, engine and gearbox failures.

The impact of system failures and atmospheric disturbances on the helicopters behaviour, including loss of tail-rotor effectiveness (LTE), are inherent in the handling and responsiveness of the model.

j2 Universal Tool-Kit System Architecture

j2 Builder Model Structure

Through the j2 Builder Graphical Interface users can add the airframe aerodynamics and additional features such as dynamic payloads, winch operations and external equipment packages. These can include aerodynamic effects, locations, and weights and balance information. All contributions are summated to a total set of values for the helicopter, automatically including orientation and moment arms. This significantly simplifies the model build process.

The integrated dynamic modelling engine enables the user to “fly” the helicopter offline or in real-time simulation through any pilot inputs and environmental conditions. The offline ability significantly reduces the time to develop and test the model, enabling structured and repeatable test to be performed during the development process without requiring extensive simulator time.

From the ‘out of the box‘ model the user can also perform the complete flight test data handling and smoothing, and flight test data matching activities to raise the fidelity to the required level. J2 Flight plug-in provides the ability to remove noise and bias from flight test data, perform QTG evaluation, and determine the necessary corrections to the model to satisfy the pass criteria.

Corrections are uniquely applied separately to rotors and airframe, maintaining the integrity of both.

This activity is complete with a fully documented process

Fully Documented Process