The proposed research seeks to develop and validate a time dependent, 3D numerical model of inclined oil-water pipe flow. Inclined oil-water flows are commonly encountered downhole in oil wells at depths where the hydrostatic pressure is too high to allow dissolved gases to come out of solution. 'Production Logging Tools' (PLTs) are used by oil companies to make fluid flow measurements in such oil wells, as part of the process of maximising oil production from UK reservoirs, and the numerical model will greatly facilitate interpretation of measurement data from these PLTs. Inclined oil-water flows are highly complex due to the presence of Kelvin-Helmholtz (K-H) waves which intermittently form and decay. The effect of these waves is to induce large, time dependent variations in the magnitude and direction of the local velocity vector of both the oil and water as well as causing large time dependent variations in the local volume fraction distribution of both phases. It is intended that the numerical model will predict the fine detail of the structure of inclined oil-water flows including (i) time dependent variations in the local velocity vector distribution of both phases; (ii) time dependent variations in the local volume fraction distribution of both phases; and (iii) the structure and propagation speed of intermittent K-H waves in the flow. If the model is successful in predicting the propagation speed of K-H waves for a wide range of flow conditions this will greatly facilitate interpretation of a novel Production Logging technique which estimates the oil-water mixture superficial velocity from measurements of the K-H wave speed. The numerical model will be validated in oil-in-water flows using a laboratory flow loop and two independent, state of the art measurement techniques which enable time dependent measurements of the local velocity vector of the dispersed phase (oil) and the local volume fraction of both phases to be measured. These techniques are; (i) high speed dual-plane Electrical Impedance Tomography (EIT) and (ii) the local, multi-sensor conductance probe. Both techniques can operate at high values of the mean dispersed phase volume fraction (e.g. for oil-in-water flows EIT operates up to about 45% oil volume fraction and the local probe operates up to about 30% oil volume fraction) where optical techniques such as PIV and LDA cannot generally be used due to the effects of light scattering from multiple oil droplet surfaces and the opacity of the oil-water mixture. Given the highly novel and innovative nature of both high speed, dual-plane EIT and the local multi-sensor conductance probe, work will be undertaken to develop these techniques such that measurements obtained from them are of sufficient accuracy to be useful in validating the numerical model. Since both measurement techniques are novel, an important feature of the proposed research will be the cross-checking of these techniques against each other.

The proposed research seeks to develop and validate a time dependent, 3D numerical model of inclined oil-water pipe flow. Inclined oil-water flows are commonly encountered downhole in oil wells at depths where the hydrostatic pressure is too high to allow dissolved gases to come out of solution. 'Production Logging Tools' (PLTs) are used by oil companies to make fluid flow measurements in such oil wells, as part of the process of maximising oil production from UK reservoirs, and the numerical model will greatly facilitate interpretation of measurement data from these PLTs. Inclined oil-water flows are highly complex due to the presence of Kelvin-Helmholtz (K-H) waves which intermittently form and decay. The effect of these waves is to induce large, time dependent variations in the magnitude and direction of the local velocity vector of both the oil and water as well as causing large time dependent variations in the local volume fraction distribution of both phases. It is intended that the numerical model will predict the fine detail of the structure of inclined oil-water flows including (i) time dependent variations in the local velocity vector distribution of both phases; (ii) time dependent variations in the local volume fraction distribution of both phases; and (iii) the structure and propagation speed of intermittent K-H waves in the flow. If the model is successful in predicting the propagation speed of K-H waves for a wide range of flow conditions this will greatly facilitate interpretation of a novel Production Logging technique which estimates the oil-water mixture superficial velocity from measurements of the K-H wave speed. The numerical model will be validated in oil-in-water flows using a laboratory flow loop and two independent, state of the art measurement techniques which enable time dependent measurements of the local velocity vector of the dispersed phase (oil) and the local volume fraction of both phases to be measured. These techniques are; (i) high speed dual-plane Electrical Impedance Tomography (EIT) and (ii) the local, multi-sensor conductance probe. Both techniques can operate at high values of the mean dispersed phase volume fraction (e.g. for oil-in-water flows EIT operates up to about 45% oil volume fraction and the local probe operates up to about 30% oil volume fraction) where optical techniques such as PIV and LDA cannot generally be used due to the effects of light scattering from multiple oil droplet surfaces and the opacity of the oil-water mixture. Given the highly novel and innovative nature of both high speed, dual-plane EIT and the local multi-sensor conductance probe, work will be undertaken to develop these techniques such that measurements obtained from them are of sufficient accuracy to be useful in validating the numerical model. Since both measurement techniques are novel, an important feature of the proposed research will be the cross-checking of these techniques against each other.

The proposed research seeks to develop and validate a time dependent, 3D numerical model of inclined oil-water pipe flow. Inclined oil-water flows are commonly encountered downhole in oil wells at depths where the hydrostatic pressure is too high to allow dissolved gases to come out of solution. 'Production Logging Tools' (PLTs) are used by oil companies to make fluid flow measurements in such oil wells, as part of the process of maximising oil production from UK reservoirs, and the numerical model will greatly facilitate interpretation of measurement data from these PLTs. Inclined oil-water flows are highly complex due to the presence of Kelvin-Helmholtz (K-H) waves which intermittently form and decay. The effect of these waves is to induce large, time dependent variations in the magnitude and direction of the local velocity vector of both the oil and water as well as causing large time dependent variations in the local volume fraction distribution of both phases. It is intended that the numerical model will predict the fine detail of the structure of inclined oil-water flows including (i) time dependent variations in the local velocity vector distribution of both phases; (ii) time dependent variations in the local volume fraction distribution of both phases; and (iii) the structure and propagation speed of intermittent K-H waves in the flow. If the model is successful in predicting the propagation speed of K-H waves for a wide range of flow conditions this will greatly facilitate interpretation of a novel Production Logging technique which estimates the oil-water mixture superficial velocity from measurements of the K-H wave speed. The numerical model will be validated in oil-in-water flows using a laboratory flow loop and two independent, state of the art measurement techniques which enable time dependent measurements of the local velocity vector of the dispersed phase (oil) and the local volume fraction of both phases to be measured. These techniques are; (i) high speed dual-plane Electrical Impedance Tomography (EIT) and (ii) the local, multi-sensor conductance probe. Both techniques can operate at high values of the mean dispersed phase volume fraction (e.g. for oil-in-water flows EIT operates up to about 45% oil volume fraction and the local probe operates up to about 30% oil volume fraction) where optical techniques such as PIV and LDA cannot generally be used due to the effects of light scattering from multiple oil droplet surfaces and the opacity of the oil-water mixture. Given the highly novel and innovative nature of both high speed, dual-plane EIT and the local multi-sensor conductance probe, work will be undertaken to develop these techniques such that measurements obtained from them are of sufficient accuracy to be useful in validating the numerical model. Since both measurement techniques are novel, an important feature of the proposed research will be the cross-checking of these techniques against each other.

To enhance ultimate recovery of hydrocarbon gases from unconventional gas resources such as shales, we need to uncover the non-intuitive gas transport mechanisms in ultra-tight porous media. Exploiting our previous and recent pioneering work in modelling rarefied gas flows at micro/nano-scales and in pore-scale characterisation of reservoir rocks, we present an ambitious project to tackle this newly-emerged research challenge through developing direct numerical simulation models and techniques that work on binarised images of concerned porous materials. This work will transform the currently-adopted heuristic approaches, i.e. Darcy-like laws and pore network modelling, into those underpinned by the first principle, and enable the quantification of prediction uncertainty on gas transport associated with the former approaches. Timely support now from EPSRC will provide us crucial resources to shape this emerging research area - understanding and quantifying gas flow physics in ultra-tight porous media.

Ammonia (NH3) is a promising zero-carbon fuel for future transportation. Today transportation emits around 8.9 billion tonnes of CO2 annually. Whilst some sectors (e.g. cars) can be decarbonised using batteries, heavier transport (marine or freight) are less likely to use batteries due to their cost and energy density. Ammonia is a hydrogen carrier, and (by volume) contains 50% more hydrogen than liquid hydrogen (which alone is extremely energy intensive to liquefy and store). Ammonia has among the highest energy densities of any non-hydrocarbon (traditionally fossil) fuel. Ammonia is particularly attractive because it can be made using the well-established Haber-Bosch process, which today is used to make 230 million tonnes of ammonia per year. Ammonia production can be 100% renewable when powered by solar and wind. This means that ammonia production can be scalable and can be undertaken repurposing a large amount of existing infrastructure. A number of pilot projects are underway worldwide with Ammonia, including for energy storage, shipping and freight transportation. Many of these are in the UK, including at the Rutherford Appleton Laboratory, Cardiff University and the University of Nottingham. However, these projects typically adapt existing technology, which is designed for a different fuel (fossil fuels usually). There is a significant lack of fundamental data to enable the design of energy conversion systems specific to ammonia. This project, AmmoSpray, aims to fill this gap. AmmoSpray will provide, for the first time, fundamental data on ammonia sprays into air. Ammonia can be sprayed into air either as a liquid or as a gas, and both will be investigated in this project. The fundamental data obtained will include spray break-up (how liquid ammonia breaks up and evaporates upon injection) and how ammonia and air mix under realistic conditions. These studies will be undertaken on three different pieces of test equipment: 1. An ambient conditions spray rig 2. A Cold Driven Shock Tube (CDST) 3. An optical access thermal propulsion system (TPS) The spray rig is fast and cheap to run, and will enable the development of the experimental systems required for this project, the testing of large numbers of spray test conditions, and will be used to undertake a scoping exercise to identify project boundaries. The CDST is a unique facility in the UK, able to replicate conditions found during combustion (150 bar pressure, 1500 K temperature) without turbulence, and with space for test equipment. This will enable for the first time imaging and break-up studies of ammonia sprays at conditions that will be seen in-use - key fundamental data. The optical TPS tests are the logical next step, adding turbulence, and replicating as closely as possible 'real' conditions, whilst still allowing access for imaging and test equipment. The key tests here will be on mixing, using a laser-based technique (PLIF) to obtain ammonia:air ratio measurements throughout the combustion volume. This will link the sprays information developed earlier to their combustion characteristics. The tests on the optical access TPS will also enable studies of how these different spray and mixing methodologies influence emissions formation for ammonia combustion, with NH3 and NOx the key emissions which will be measured. This step-by-step nature is perfectly suited for improving existing models. The data obtained will be coded into commercial modelling software (computational fluid dynamics (CFD)) provided by project partner, Convergent Science. Its CONVERGE CFD software is used by companies globally. The data obtained will be used to develop models for ammonia spray break-up, mixing, and emissions formation upon combustion. This will all happen in parallel with the experimental program and will ensure that the project's utility well beyond the project itself, with the models developed being available to be used by any of the global users of the software.