Virtual Reality (VR) allows engineers to naturally interact with three-dimensional digital models in a three-dimensional space. This provides a unique interface between users and computer models not found in traditional desktop environments. Common uses of virtual reality in product design include prototype evaluation, virtual assembly and visualization of engineering analysis results. This work described in this paper is based on a methodology for interactive design that uses virtual reality as an interface to product design and analysis. Computer analysis models coupled with fast reanalysis approximations and geometric models in a virtual environment are developed to facilitate shape design changes and updated analysis results in real-time. This combined design and analysis environment encourages the rapid investigation of many possible shape and design changes and how they affect the final product performance. The application developed to test this methodology is referred the Immersive Virtual Design Application (IVDA).