Structured Mesh Generation and Numerical Analysis of a Scroll Expander in an Open-Source Environment

Abstract

The spread of the organic rankine cycle applications has driven researchers and companies to focus on the improvement of their performance. In small to medium-sized plants, the expander is the component that has typically attracted the most attention. One of the most used types of machine in this scenario is the scroll. Among the other methods, numerical analyses have been increasingly exploited for the investigation of the machine’s behaviour. Nonetheless, there are major challenges for the successful application of computational fluid dynamics (CFD) to scrolls. Specifically, the dynamic mesh treatment required to capture the movement of working chambers and the nature of the expanding fluids require special care. In this work, a mesh generator for scroll machines is presented. Given few inputs, the software described provides the mesh and the nodal positions required for the evolution of the motion in a predefined mesh motion approach. The mesh generator is developed ad hoc for the coupling with the open-source CFD suite OpenFOAM. A full analysis is then carried out on a reverse-engineered commercial machine, including the refrigerant properties calculations via CoolProp. It is demonstrated that the proposed methodology allows for a fast simulation and achieves a good agreement with respect to former analyses.

Performance Analysis and Test Research of PEMFC Oil-Free Positive Displacement Compressor for Vehicle

“…The closer the scroll tooth wall, the greater the change in temperature and velocity. In the working chamber, the temperature of prototype SC2 increased by 28.42 K, the pressure increased by 1.5 kPa, and the velocity increased by 19.34 m/s , compared with SC1.…”

“…Zhao et al [18] conducted three-dimensional unsteady-state numerical simulation of compression and found that the shape and area of the compressor inlet will affect the pressure distribution in the discharge chamber. Fadiga et al [19] proposed a special grid generation method based on the open source CFD software OpenFOAM, which can quickly generate a fluid domain grid that matches the working fluid, so that the grid can make the scroll machinery's working area match well with the fluid working medium. Cavazzini et al [20] combined CFD and PSO (particle swarm optimization) algorithms and found that the radius of gyration, the number of scroll teeth, and the size of the exhaust port all have an impact on the output characteristics of the scroll compressor.…”

Organic Rankine Cycle for Energy Recovery System

“…This book contains the successful invited submissions [1][2][3][4][5][6][7][8][9] to a Special Issue of Energies entitled "Organic Rankine Cycle for Energy Recovery System", focusing on a modern technology committed to energy saving and thus capable of producing positive environmental outcomes. Indeed, the organic Rankine cycle (ORC) is a thermodynamic concept already demonstrated as an engineering viable solution for waste heat recovery systems.…”

“…Fadiga et al [8] perform a numerical analysis based on dynamic mashing technique of a volumetric expander of scroll type design for ORC application.…”

Transient Thermodynamic Modeling of a Scroll Compressor Using R22 Refrigerant

“…A major issue in the design is the shape of the scroll, which has a significant impact on compression performance. Numerous researchers contributed to the development of the design technique for the scroll shape [2][3][4][5][6][7][8][9][10]. Each scroll curve was defined as a circular involute, which is a practical and a classical method to predict its dynamic behavior.…”