Improving the Performance of the Hardy Cross Algorithm For Large Ventilation Models


Craig Stewart, Howden Simsmart Ventsim; Saiied Aminossadati, The University of Queensland; Mehmet Kizil, University of Queensland

The Hardy Cross algorithm offers a reliable method of solving network systems of fluid flow and has become widely used for solving water and ventilation flow networks.  A limitation is that computational iterations and time to solve a network rises rapidly with the size of the model and modern detailed ventilation networks have typically grown to thousands of airways. Non-linear matrix solving methods can offer improved performance, however these are more complex and may be unstable if initial estimates are poor.  This paper presents improvements that can be applied to the traditional Hardy Cross algorithm to greatly reduce iterations and solving time for large ventilation models.