QPAC is a general-purpose modelling tool for solving systems of partial differential and algebraic equations. It is used to provide a comprehensive mathematical modelling consultancy service, addressing a wide range of problems including those with strongly coupled nonlinear processes. The flexibility and power of QPAC allow it to be applied to a wide array of problems, as demonstrated by the collection of peer-reviewed publications and white papers listed below.
For a comprehensive overview of the capabilities of QPAC and the design philosophy behind it, together with examples of its use in the fields of energy and the environment, please download the QPAC Overview Report.
The following is a selection of peer-reviewed publications and white papers on coupled nonlinear modelling problems where QPAC has been applied:
- Value of abstraction in performance assessment – When is a higher level of detail necessary?. Geomechanics for Energy and the Environment vol 39, 100577, ISSN 2352-3808 (2024).
- Synthesis of results for Brine Availability Test in Salt (BATS) DECOVALEX-2023 Task E. Geomechanics for Energy and the Environment vol 39, 100581, ISSN 2352-3808 (2024).
- Near-Field Coupled Processes in Salt-Based Disposal Facilities -- Learning from Modelling in DECOVALEX 2023. WM2022 Conference (2022).
- Brine Availability Test in Salt: International Collaborative Modeling in the DECOVALEX Project – 22164. WM2022 Conference (2022).
- Modelling advective gas flow in compact bentonite: Lessons learnt from different numerical approaches. International Journal of Rock Mechanics and Mining Sciences, vol 139 (2021).
- Development of an upscalable HM model for representing advective gas migration through saturated bentonite. International Journal of Rock Mechanics and Mining Sciences vol 133 (2020).
- Avoiding unrealistic behaviour in coupled reactive-transport simulations of cation exchange and mineral kinetics in clays. Clay Minerals vol 54, 83-93 (2019).
- Gas transport modelling at different spatial scales of a geological repository in clay host rock. Environmental Earth Sciences vol 78, 221 (2019).
- DECOVALEX-2019 project: Task A - modElliNg Gas INjection ExpERiments (ENGINEER). British Geological Survey Open Report OR/18/049 (2018).
- Numerical modelling of gas flow in a compact clay barrier for DECOVALEX-2019. Second International Discrete Fracture Network Engineering Conference (2018).
- Coupled reactive transport modelling of the international Long-Term Cement Studies project experiment and implications for radioactive waste disposal. Applied Geochemistry vol 97, 134-146 (2018).
- Modeling the Long-Term Behavior of Cementitious Barriers -18188. WM2018 Conference, WM Symposia, Inc (2018).
- Geochemical Modelling of the LCS Experiment. QRS-1523D-2, RWM Report (2017).
- Reactive transport modelling of a shale-bentonite interface in a hypersaline system. Applied Geochemistry vol 76, 60-73 (2017).
- A synthesis of approaches for modelling coupled thermal–hydraulic–mechanical–chemical processes in a single novaculite fracture experiment. Environmental Earth Sciences vol 76, 12 (2016)
- Development of approaches for modelling coupled thermal–hydraulic–mechanical–chemical processes in single granite fracture experiments. Environmental Earth Sciences vol 75, 1313 (2016).
- Evaluating the importance of different coupled thermal, hydraulic, mechanical and chemical process simulations during fluid flow experiments in fractured novaculite and fractured granite. Environmental Earth Sciences vol 75, 1133 (2016).
- Comparative modelling of laboratory experiments for the hydro-mechanical behaviour of a compacted bentonite–sand mixture. Environmental Earth Sciences vol 75, 1311 (2016).
- Engineered damage zone sealing during a water injection test at the Tournemire URL. Environmental Earth Sciences vol 75, 933 (2016).
- A new hydro-mechanical model for bentonite resaturation applied to the SEALEX experiments. Environmental Earth Sciences vol 75, 974 (2016).
- Multi-scale gas transport modelling for the EC FORGE project. Mineralogical Magazine vol 79, 1251-1263. (2015).
- Application of hybrid numerical and analytical solutions for the simulation of coupled thermal, hydraulic, mechanical and chemical processes during fluid flow through a fractured rock. Environmental Earth Sciences vol 74, 7837-7854 (2015).
- Comparison of the impacts of elevated CO2 soil gas concentrations on selected European terrestrial environments. International Journal of Greenhouse Gas Control vol 42, 357-371 (2015).
- Thermodynamic and fully-coupled reactive transport models of a steel–bentonite interface. Applied Geochemistry vol 61, 10-28 (2015).
- Potential migration of buoyant LNAPL from Intermediate Level Waste (ILW) emplaced in a geological disposal facility (GDF) for UK radioactive waste. Journal of Contaminant Hydrology vol 167, 1-22 (2014).
- Systems analysis of field and laboratory experiments considering impacts of CO2 leakage in terrestrial systems. Energy Procedia vol 37, 3394-3402 (2013).
- Analysis of hydro-mechanical processes in a ventilated tunnel in an argillaceous rock on the basis of different modelling approaches. Journal of Rock Mechanics and Geotechnical Engineering vol 5, 1-17 (2013).
- Reactive and non-reactive transport modelling in partially water saturated argillaceous porous media around the ventilation experiment, Mont Terri. Journal of Rock Mechanics and Geotechnical Engineering vol 5, 44-57 (2013).
- Approaches for representing hydro-mechanical coupling between sub-surface excavations and argillaceous porous media at the ventilation experiment, Mont Terri. Journal of Rock Mechanics and Geotechnical Engineering vol 5, 85-96 (2013).
- Coupled hydro-mechanical-chemical process modelling in argillaceous formations for DECOVALEX-2011. Mineralogical Magazine, December 2012, vol 76(8), pp. 3131-3143 (2012).
- The long-term cement studies project: the UK contribution to model development and testing. Mineralogical Magazine, December 2012, vol 76(8), pp. 3445-3455 (2012).
- SR-Site Independent Modelling of Engineered Barrier Evolution and Coupled THMC: Contribution to the Initial Review Phase. Swedish Radiation Safety Authority (SSM) Report 2012:18 (2012).
- Assessment of Issues Relating to Pre-closure to Post-closure Gas Generation in a GDF. Quintessa Report QRS-1378ZP-R1 v3.0 to NDA RWMD, available from the NDA bibliography (2012).
- Analysis of Barrier Performance: Modelling of Copper Corrosion Scenarios with and without Buffer Erosion. Swedish Radiation Safety Authority (SSM) Report 2011:12 (2011).
- Investigation of Gas Generation and Resaturation Issues: Input to EC FORGE Project. Quintessa Report QRS-1378ZC-R2 v2.0 for NDA RWMD, available from the NDA bibliography (2011).
- Optimisation of Deep Geological Disposal of Graphite Wastes. Quintessa Report QRS-1378ZO-R1 v2.0 for NDA RWMD, available from the NDA bibliography (2011).
- Fully Coupled Modeling of Long Term Cement Well Seal Stability in the Presence of CO2. Energy Procedia 4:5162-5169 (2011).
- Testing Geochemical Models of Bentonite Pore Water Evolution Against Laboratory Experimental Data. Physics and Chemistry of the Earth 36:1817-1829 (2011).
- A Comparative Study of the Modelling of Cement Hydration and Cement-Rock Laboratory Experiments. Applied Geochemistry 26:1138-1152 (2011).
- Front Tracking using a Hybrid Analytical Finite Element Approach for Two-Phase Flow Applied to Supercritical CO2 Replacing Brine in a Heterogeneous Reservoir and Caprock. Transport in Porous Media 90:545-573 (2011).
- Natural Systems Evidence for the Alteration of Clay under Alkaline Conditions: an Example from Searles Lake, California. Applied Clay Science 47:72–81 (2010).
- Modelling Iron-Bentonite Interactions. Applied Clay Science 47:91-98 (2010).
- Modelling Coupled Processes in the Evolution of Repository Engineered Barrier Systems using QPAC-EBS. Swedish Radiation Safety Authority (SSM) Report 2010:25 (2010).
- An Evaluation of Models of Bentonite Pore Water Evolution. Swedish Radiation Safety Authority (SSM) Report 2010-12 (2010).
- Post-closure Performance Assessment: Consideration of a Co-located Geological Disposal Facility in the Safety Case. Quintessa Report QRS-1378P-R1 v2.1 for NDA RWMD, available from the NDA bibliography.
- Understanding Radionuclide Migration from the D1225 Shaft, Dounreay, Caithness, UK. MRS Proceedings 1193 (2009).
- Modelling the Fate of Carbon Dioxide in the Near-surface Environment at the Latera Natural Analogue Site. Energy Procedia 1:1879–1885 (2009).
- Independent Calculations for the SR-Can Assessment: External Review Contribution in Support of SKI’s and SSI’s Review of SR-Can. Swedish Nuclear Power Inspectorate (SKI) Report 2008-12 (2008).