Abstract
Water-pumping windmills are reliable alternatives to provide water in some areas isolated from the electricity network, especially those with poor wind sources that are insufficient to operate wind turbines to generate electricity. The successful design of windmills for water pumping requires careful study of many variable parameters depending on the wind pattern and topography of the site. However, in this study, the researchers relied on the application of an integrated approach between forwarding Engineering (FE) and Reverse Engineering (RE), with the aim of obtaining a 3D CAD model of a water pumping windmill system.This 3D model will be the basis for manufacturing the windmill prototype that will be installed at a pilot site in a suburb of the city of Tajoura within a research project. The FE activities cannot be neglected when applying RE for the successful manufacturing of the windmills. The wind data recorded at the Center for Solar Energy Research and Studies (CSERS) for several years was used for calculating daily and monthly average wind speed and studying the daily wind pattern. The analysis of the collected wind data showed that the minimum and maximum daily average wind speed at Tajoura varies from 2.35m/s to 4.69 m/s, and theannual average wind speed is 3.24m/s. Among the Forward design, activity is estimating the wind resources available at the site for sizing the system to provide the site water requirements of 5 m³/day. From this point on, a commercial water-pumping windmill of 4.88m (16ft and a standard tower height of 12m were chosen to be the target of a RE application to obtain a CAD model. RE is accomplished in three phases: digitizing the component (part), processing the measured data, and creating the CAD model. To adopt the 3D model for all parts, they must be compared with the original scanned data using Deviation Analysis in CATIA. Afteradopting the 3D models of all the system components, the 3D assembly models were created based on the integrated approach between RE and FE. Finally, it is worth noting that the windmills for water pumping could not be manufactured solely by just applying reverse engineering.

Key words: Windmills, Rotor, Wind Speed, CAD, CATIA, Mesh, Point cloud, Laser Scanning