Evolution Of Design Methodologies Research Articles

UAV Design and Configuration Aerodynamics - An ADE Experience

UAVs are becoming an essential part of the modern defense forces world over in the recent years. They are widely used for surveillance, reconnaissance, target for missiles and combat. They are available in various weight classes from few kilograms to tons. Apart from design of aircraft, establishing an accurate aero data base for control law design for the aircraft is a main challenge in itself. Aeronautical Development Establishment (ADE) is involved in the design and development of many UAVs for the last 30 plus years and has experienced several challenging design and engineering problems. Over the years, various UAVs like Ulka, Sparrow, Lakshya, and Nishant for different mission requirements have been designed and developed. The evolution of design methodology in ADE and the present configuration design activities of UAVs and aircraft stores separation studies with a focus on CFD are discussed in this paper.

High-Level Models for Transformation-Oriented Design of Hardware and Embedded Systems

Abstract —Evolution of design methodologies follows a common trail: technology scaling leads to growing design complexity and rising abstraction level in the domain. Introduction of new (higher) abstraction levels emphasizes the importance of reuse and transformations. The design process can be seen as a sequence of high-level transformations from the higher-level specification to the lower-level one. We analyze high-level modeling and metaprogramming techniques for supporting transformations based on domain variability models. Next, we present a reuse evolution model for domain component design at a higher abstraction level to support the transformation-oriented approaches. Finally, high-level modeling techniques (UML-domain language metamodels for domain code generation, parameterized UML classes for template metaprogramming, feature models for explicit representation of variability) for specification of transformations and metaprograms are analyzed. Index Terms —design automation, transformation, hardware and embedded system design

Evolution of Design Methodologies for Next Generation of Reactor Pressure Vessels and Extensive Role of Thermal-Hydraulic Numerical Tools

The thermal-hydraulic design of the first pressurized water reactors was mainly based on an experimental approach, with a large series of tests on the main equipment [control rod guide tubes, reactor pressure vessel (RPV) plenums, etc.] to check performance.Development of computational fluid dynamics codes and computers now allows for complex simulations of hydraulics phenomena. Provided adequate qualification, these numerical tools are an efficient means to determine hydraulics in the given design and to perform sensitivities for optimization of new designs. Experiments always play their role, first for qualification and then for validation at the last stage of the design. The design of the European Pressurized Water Reactor (EPR), jointly developed by Framatome ANP, Electricité de France (EDF), and the German utilities, is based on both hydraulics calculations and experiments handled in a complementary approach.This paper describes the collective effort launched by Framatome ANP and EDF on hydraulics calculations for the RPV of the EPR. It concerns three-dimensional calculations of RPV inlets, including the cold legs, the RPV downcomer and lower plenum, and the RPV upper plenum up to and including the hot legs. It covers normal operating conditions but also accidental conditions such as pressurized thermal shock in a small-break loss-of-coolant accident. Those hydraulics studies have provided much useful information for the mechanical design of RPV internals.