Challenge

When a leading transatlantic aerospace equipment and systems company designed a completely new system for providing supplemental power and cooling for military and civil aircraft engines, the Technology Group at MPR Associates was the first choice among engineering firms for validating the design.  With deep expertise in system engineering and dynamic system modeling, MPR assembled a multi-disciplined team to create a dynamic model for evaluating how the client's conceptual design would behave under certain flight conditions such as altitude and aircraft speed.  The client wanted to better understand how to specify and design a control system while recognizing transient performance. 

A key driver of the project was the need to demonstrate within the organization as well as to the Air Force Research Lab and one of the client's civil aircraft manufacturers that the system would operate in accordance with its design.

Approach

MPR's proven approach for this client started with technology assessment and concept definition.  MPR first reviewed and analyzed what the client had created to date against first principles engineering, the concept of referring back the fundamental scientific laws that describe the behavior of physical systems.  Many engineering solutions are based on "handbook" solutions that rely on embedded simplifying assumptions and empirical data, which can result in solutions where the design margin and assumptions are not well understood.  By referring back to first principles, MPR can fully understand any simplifying assumptions made and can accurately assess design margins.  For this client, MPR used first principles engineering, including conservation of mass, momentum and energy, to develop the basis for the modeling approach and defined the simplifying assumptions. 

After the initial analysis was complete, MPR developed independent models to evaluate certain aspects of the client's system.  Creating a model using MATLAB/Simulink, a platform for multi-domain simulation and model-based design for dynamic systems, the team generated predicted results for defined transients and validated system design performance.  MPR designed the models for both steady state and transient conditions.  Transient modeling, which tests the integrated cooling and heating system under real operation and environmental conditions, included changes in speed, altitude and sudden movement.  Through these models, MPR independently validated that the client had made reasonable assumptions in its initial design.

Solution

    MPR utilized dynamic modeling to analyze the system, document the results and validate the conceptual design.  Following this process, MPR's project team made recommendations to the client and implemented various improvements to the client's original system model.  Once the modifications were completed, the team again conducted testing to ensure the modified system model's validity.  The client is currently developing a functional prototype of this system. 

    Benefits

    MPR's client benefited from the team's knowledge and experience in thermo hydraulics and turbo machinery systems.  The client gained approval for the next phase of development thanks in part to MPR's expertise in analyzing and evaluating a proof of concept design through independent modeling.