The Cambridge CFD (computational fluid dynamics) Grid is a distributed problem-solving environment for large-scale CFD applications set up between the Cambridge eScience Centre and the CFD Laboratory in the Engineering Department at the University of Cambridge. A Web portal, the Cambridge CFD Web Portal (CamCFDWP) has been developed to provide transparent integration of CFD applications to non-computer scientist end users. In addition to the basic services provided of authentication, job submission and file transfer, the CamCFDWP makes use of XML (extensible markup language) techniques which make it possible to easily share datasets between different groups of users. A Web service interface has recently been implemented for a CFD database which could be integrated in the CamCFDWP in the near future. We also review how this Web service can be made secure using SSL, XML signatures and XML encryption.