Modelling and Simulation: For Engineering project

Modelling and Simulation Model: A system of postulates, data and interfaces presented as a mathematical description of an entity or proceedings or state of affair. (Development of equations, constraints and logic rules) Simulation: Exercising the model and obtaining results. (Implementation of the model) Simulation has emerged as the Third methodology of exploring the truth. It would complement the theory and experimental methodology. Simulation will never replace them. Simulations are applicable in the following situations: 1. When operating conditions change e.g. temperature, pressure, etc 2. When non-controllable factors change e.g. weather, earthquake 3. Dependence of variation of critical factors e.g. fatigue, resonance may be destructive. 4. How sensitive is one factor to the changes in another? 5. Other benefits: a) Useful in design b) Study effects of constraints c) Increase understanding 6. Pitfalls: An assumption, which the owner can’t model or verbalise; so when two independent models clash, contradictory results arise Advantages of simulation Saves manpower, material Useful even if not possible by other means Saves money with fast, consistent answers Could be used for education after establishing Increased flexibility, accuracy, range of operation New results not available before Improved results due to standardization Increased understanding Explicitly stated assumptions and constraint Requirements/ skill required Computer Skill/Expertise Time for implementation Drawbacks: Modelling errors at different levels – Scientific model of reality – Mathematical model – Discrete numerical model – Application program model – Computational model Input errors: Out of range inputs can give spurious results Precision errors: Limits in the precision Phases of development of simulation model Real system to mathematical model Algorithm to solve mathematical model Implementation on a computer Validation – User with I/O – Model – Evaluations Simulation