Tests supporting Republic of Korea submarine programme

Model testing

Model trials in instrumented tanks and open reservoirs allow submarine manoeuvring performance to be assessed in various shallow and deep operating scenarios without reliance on extended mathematical extrapolation, producing substantiated results by actual model manoeuvring tests, and thus providing an absolute level of assurance of the safe operating limits of the submarine before it goes to sea.

Safe operating envelope
Daewoo Shipbuilding & Marine Engineering Co. Ltd (DSME) were selected by the Korean Defense Acquisition Program Administration to build two 3000 ton conventional submarines . The project, called Jangbogo-III, will deliver next generation submarine capability for the Korean Navy.

DSME were seeking a partner with an extensive proven track record in conducting submarine free running model test programmes to support the design and development phase and de-risk the programme. The major requirement was to validate and assure the hydrodynamic and manoeuvring performance of the proposed submarine design.

QinetiQ built and tested a free running model for the Jangbogo-III programme, in order to inform the customer’s critical design review (CDR) and establish the submarine safe operating envelope through the use of independent submarine research model testing capability and expertise as used by the Royal Navy and other worldwide organisations.

The challenge
Free running submarine model experiments in a deep water facility allow the full depth envelope to be achieved (at scale), providing a more robust validation of developed mathematical models against physical data right up to the extremes of the submarine’s operational limits. This demonstrates that the full scale as built submarine will perform as specified and expected over its complete depth range. This provides significant de-risking to submarine programmes and ultimately the safety of personnel at sea.

A full programme of submerged manoeuvring experiments were conducted by QinetiQ at a deep water reservoir facility and in QinetiQ’s Ocean Basin, the largest basin in Europe.

Following deep water experiments, the mathematical model was validated against the full speed and depth envelope of real physical data. The test programme extended beyond the submarine’s operational limits providing confidence in performance.

Benefits and returns
One of the rationales for free running model tests is to validate the design mathematical model for manoeuvring, and make changes to the derivatives (or the mathematical model itself) where necessary to improve fidelity.

With QinetiQ’s experience of making improvements to uncertain mathematical models based on free running model experiments and full scale trials it was, with through a carefully designed test programme, possible to improve mathematical models to fit the observations.

Exacting standards in submarine design, training and maintenance reduce the incidences of accidents and catastrophic failures.

The programme of work resulted in the Jangbogo-III submarine build programme being able to proceed with the assurance of design validation through use of the independent QinetiQ submarine research model testing capability.

Unique experience
QinetiQ has an unrivalled knowledge and experience in the field of submarine manoeuvring and control performance, design, optimisation. Its services are underpinned by an investment in facilities and equipment valued at more than £100 million. QinetiQ provides solutions throughout the lifecycle from concept design, through manufacture, to in-service and disposal including planning and acquisition, safety and assessment, stealth management, ranging, command information systems and marine structural analysis and technical support.