Mathematical and CFD modelling of a motor powered by latent heat of condensation
Joint MASCOS and Department of Mathematics and Statistics Colloquium
by Dr Noel Barton
Abstract: The Bernoulli Effect for a compressible gas shows there will be a drop in pressure, temperature and density when the gas speed increases isentropically in the narrowing section of a duct. For saturated moist air, the temperature drop can lead to rapid condensation of microscopic water droplets and release of latent heat. If the droplets are collected and thereby prevented from re-evaporation, we find that when the flow has slowed down isentropically at the duct outlet, the pressure of the energised flow will be - in theory - greater than the inlet pressure. Surplus pressure can be used to drive a turbine for electrical or mechanical power.
The lecture will present mathematical models for the proposed motor. The models will include a one-dimensional cross-sectionally averaged thermodynamic model to predict theoretical power output and efficiency, diffusion models for droplet growth and latent heat release, and estimates for dimensions of the device.
In theory, the motor will deliver power (electrical or mechanical) and chilled distilled water as co-products. In the real world, feasibility of the motor is far from certain; triumph of utility over futility will require brilliant engineering to overcome numerous practical difficulties, as well as inspired design based on extensive Computational Fluid Dynamics simulations. The lecture will finish with a description of CFD work in progress.
For More Information: Paul Norbury tel. 8344 5534 http://www.ms.unimelb.edu.au/~pnorbury/colloquium/colloquium-2005.html