Current Interest

• Numerical Modelling

• Modern Manufacturing Techniques

• Solving Optimization Problems

• Additive Manufacturing

• Aerodynamics and Hydrodynamics

Doctoral Research (Development of a Ship-Routing Algorithm)

Weather routing of ships is an important consideration in navigation which is essentially concerned with establishing an optimal route (the most economical route) from a departure: source to arrival point: destination by applying available information of the weather condition viz. wind, wave and current along with the behaviour of ship. In the present work an attempt has been made to formulate a mathematical model to determine an optimal path for ship routing by applying optimal control theory in conjunction with hydrodynamics and weather forecasting tools. This problem is also referred to as ‘Weather routing’ or ‘Ship weather routing’.

Information on ship speed loss due to weather condition effects is precomputed using seakeeping computing tools (priorly, developed by IIT-Kharagpur) which are then effectively employed in the optimum ship routing algorithm. Wave forecasts are provided in a deterministic setting by a third generation numerical ocean wave prediction model (WAM). Dijkstra’s path optimisation scheme which employs optimal control theory and dynamic programming technique is used to obtain optimum route in a given random sea state. The concept of an ‘objective function’ or the weight function used in optimization techniques, which needs to be minimised in the context of optimization algorithm is described. For minimum time route, suitable approximate expressions are made for determining the reduced speed after taking into account the environmental factors.

The developed algorithm investigated through various realistic wave information (e.g. wave height and wave direction) obtained from WAM. Illustrative minimum-time sea routes on Arabian- Sea and Bay -of- Bengal for different ships have been determined.All relevant practical and realistic constraints viz. presence of land boundaries, avoiding non navigable water, effects of wind and current, voluntary speed reduction (with various safety constraints), considerations for changing wave conditions with time etc. are also incorporated in the framework of the algorithm.

The problem formulation adopted dynamic programming (DP) which is most suitable for implementation of computer optimization techniques. By utilizing the hydrodynamic results (various resistances: still water resistances+added resistance+wind resistance etc. and safety constraints: slamming, roll acceleration, heave motion etc.) and weather information viz. outputs from wave model, a mathematical model/a numerical is developed (written in C/C++). Results from the developed mathematical model are plotted by using “ArcGis3.2” to generate various routes on a geographical map.