Expansions in the Non-Ideal Compressible Flow Regime: A Numerical and Experimental Study

Organic Rankine Cycle systems are gaining increasing attention as a modular, cost-effective and decentralised thermal energy recovery solution. The design of an efficient expander in the ORC system is crucial to its rapid uptake by the industry. Compared to volumetric expanders, a radial turbine provides advantages in terms of flexibility and...

A Validation Infrastructure for Non-Ideal Compressible Fluid Dynamics: with applications to ORC Turbines

The objective of this thesis was to further the validation effort on the SU2 flow solver for non-ideal compressible flows. To do so, an uncertainty quantification infrastructure based on the V&V20 validation standard was developed. To determine whether a model error was present, the different sources of uncertainty were combined and then...

Performance Limit of Centrifugal Compressor Operating with Non-Ideal Compressible Flow

The use of centrifugal compressors is widespread in many different industrial applications, namely refrigeration cycles, oil and gas rotating equipments, automotive turbochargers and small aero-engines. Compared to their axial counterpart, centrifugal compressors can provide the same compression ratio within less compression stages, trading-off...

Formation of Rarefaction Shockwaves in Non-ideal Gases with Temperature Gradients

The nonlinear propagation of finite amplitude waves in the non-ideal compressible fluid dynamic (NICFD) region of high-molecular weight fluids, and in particular in cases where non-classical gas dynamic phenomena like the formation of rarefaction shock waves may be expected, is of great scientific interest. Almost all the theoretical...

Simulation of Two-Dimensional Steady State Boundary Layers Applied to Nonideal Gas Flows

Organic Rankine Cycle (ORC) Power Plants can be of greatimportance in the energy transition as they are suitable for converting wasteheat to power and can utilize renewable energy for their operation. To improvethe efficiency of ORC Power Plants, the physical phenomena inside thesemachines must be understood....

Validation of the SU2 Flow Solver for Classical Non Ideal Compressible Fluid Dynamics

The validation of SU2 for modelling classical non-ideal compressible fluid dynamics will advance the research into efficient ORC turbomachinery design. This study determines the validity of the two-dimensional flow solver for predicting the isentropic expansion of Siloxane MM through a converging-diverging nozzle using...

A look-up table method based on unstructured grids and its application to non-ideal compressible fluid dynamic simulations

Fast and accurate computation of thermo-physical properties is essential in computationally expensive simulations involving fluid flows that significantly depart from the ideal gas or ideal liquid behavior. A look-up table algorithm based on unstructured grids is proposed and applied to non-ideal compressible fluid dynamics simulations. The...

Unsteady simulation of quasi-periodic flows in Organic Rankine Cycle cascades using a Harmonic Balance method

Currently, turbomachinery design optimization methodologies are mainly restricted to steady state approaches, due to the high computational cost associated with time-accurate shape optimization algorithms. However, the possibility to include unsteady effects in turbomachinery optimization can significantly increase the level of accuracy of...