James Rouse

University of Nottingham | Notts · Department of Mechanical, Materials and Manufacturing Engineering

Adiabatic Compressed Air Energy Storage (ACAES) is regarded as a promising, grid scale, medium-to-long duration energy storage technology. In ACAES, the air storage may be isochoric (constant volume) or isobaric (constant pressure). Isochoric storage, wherein the internal pressure cycles between an upper and lower limit as the system charges and di...

Energy storage will be required over a wide range of discharge durations in future zero-emission grids, from milliseconds to months. No single technology is well suited for the complete range. Using 9 years of UK data, this paper explores how to combine different energy storage technologies to minimize the total cost of electricity (TCoE) in a 100%...

For critical component application, such as aerospace turbine rotors, it is imperative to be able to make accurate in-service material behaviour and component life predictions for both design and monitoring of component life. The development of such predictive capability is dependent on the quality of the experimental data from which the material p...

This paper explores how the requirement for energy storage capacity will grow as the penetration of renewables increases. The UK’s electric grid is used as a case study. The paper aims to provide insight on what is the most economical solution to decarbonize the electric supply. A two-dimensional study varying the penetrations of wind and solar PV...

The present work introduces a small volume, high throughput testing method that may be used to quickly, and with high spatial fidelity, investigate local material properties in additively manufactured materials. A case study application is presented here, considering components made from the alloy Ti-6Al-4V by the powder bed fusion process. Novel t...

Curved laminates in aero-structures, such as the L-angle sections where webs and flanges meet, are prone to delamination due to high interlaminar stresses in these regions. Some efforts to investigate delamination in these structures can be found in the literature but commonly structures are limited to unidirectional layups or modelling approaches...

The current paper presents work on identification and evaluation of a range of factors influencing accuracy and comparability of data generated by three laboratories carrying out stress-controlled thermo-mechanical fatigue crack growth tests. It addresses crack length measurements, heating methods and temperature measurement techniques. It also pro...

The polycrystalline nickel-base superalloy RR1000 is used as turbine rotor material in Rolls-Royce aero engines and has to withstand a wide variety of load and temperature changes during operation. In order to maximize the potential of the material and to improve component design, it is of great interest to understand, and subsequently be able to a...

An understanding of rate dependency over a wide range of time scales is vitally important in approximating the transient response of critical components operating in extreme environments. Many examples of viscoplastic model formulations can be found in the literature, wherein all rate dependency is assumed to occur after yielding. Such models negle...

Non-destructive testing techniques are widely applied in industry for the evaluation of quantities of interest without inflicting additional damage accumulation. Crack detection and monitoring is a prime example of where non-destructive testing is valuable. Among the variety of non-destructive testing techniques, the direct current and alternating...

The current paper describes TMF crack growth behaviour in an advanced nickel-based superalloy. Changes in behaviour are examined which occur as a function of the phase angle between applied stress and temperature. The fractography of the failed specimens reveals changes from transgranular to intergranular growth between high and low phase angle tes...

This paper explores the use of steel wire wound pressure vessels for reducing the cost of aboveground air storage for small-scale CAES systems. CAES technology is often only considered for large scale applications because underground salt caverns are only cost-effective for capacities in the order of hundreds of MWh. Besides the size restriction, C...

The wide scale market penetration of numerous renewable energy technologies is dependent, at least in part, on developing reliable energy storage methods that can alleviate concerns over potentially interrupted and uncertain supplies. Many challenges need to be overcome, not least among them is allowing capacity for the wide range of time scales re...

The trend in power generation to operate plant with a greater frequency of on/partial/off load conditions creates several concerns for the long term structural integrity of many high temperature components. The Green's function method has been used for many years to estimate the thermal stresses in components such as steam headers by attempting to...

Rapid thermal ageing has been observed in the literature for certain aerospace aluminium alloys under conditions which are foreseeable in their intended component applications. While several experimental programs have explored this phenomenon in the laboratory, efforts to incorporate these effects in unified constitutive models have, to date, been...

Societal and environmental pressures are forcing thermal power plant operators to deviate greatly from the generation strategies of the past. The application of high frequency start up/shut down/partial load cycles to components that may well be outside their design life makes research into the long-term integrity of at risk assets paramount. Decou...

Improving the understanding of the long term rate dependent behaviour of materials is of critical importance in many engineering applications. Without this understanding, it is potentially difficult to ensure safe and effective plant operation while simultaneously satisfying requirements for sustainability and responsible resource management. In th...

Crack size determination using electrical potentials both in service and in the laboratory has been undertaken for many years. In the laboratory this has mainly concentrated on the measurement of crack depth, with either alternating current (AC) or direct current (DC) supplies. Some work to determine the varying depth along the width of cracks as a...

A fatigue crack initiation model based on damage accumulation via a fatigue memory surface in conjunction with a plastic strain energy parameter was evaluated for thermomechanical fatigue loading in a gas turbine disc alloy. The accumulated damage in each hysteresis loop was summed up, and it was assumed that the damage at the stable state is repea...

The optimization of a packed bed for utility-scale applications is presented herein. The paper comprehensively discusses the effects that particle size, aspect ratio and storage mass have on the exergy losses of the store throughout a complete working-cycle and seeks to provide a clear reference of what is an adequate range of aspect ratios to cons...

The wide scale market penetration of numerous renewable energy technologies is dependent (at least in part) on energy storage. Many challenges need to be overcome, not least among them is allowing capacity for the wide range of time scales required to ensure grid stability. At present (in thermal power plant), high frequency/short duration (acting...

Packed bed thermoclines have attracted considerable interest as an economical method for storing large amounts of thermal energy. This thermal energy can either be used directly as heat or can be converted to electricity via a range of proposed techniques such as Adiabatic Compressed Air Energy Storage (ACAES), Wind driven Thermal Pumping (Wind-TP)...

To date, the complex behaviour of small punch creep test (SPCT) specimens has not been completely understood, making the test hard to numerically model and the data difficult to interpret. This paper presents a novel numerical model able to generate results that match the experimental findings. For the first time, pre-strained uniaxial creep test d...

P91 martensitic steel has now been widely used for power plant components such as steam pipe sections and headers. With the shift to renewable sources, traditional fossil power plants are increasingly expected to operate under so called “two shifting” conditions (high frequency start up/shut down cycles from a partial load condition) to match marke...

Societal pressures are mounting on electricity operators to operate traditional fossil-fuel power plants in an efficient and flexible manner in conjunction with renewable power plants. This requires the uses of high frequency start up – shut down load profiles in order to better match market demands. As such, high temperature/pressure components su...

The threat of thermal fatigue is an increasing concern for thermal power plant operators due to the increasing tendency to adopt "two-shifting" operating procedures. Thermal plants are likely to remain part of the energy portfolio for the foreseeable future and are under societal pressures to generate in a highly flexible and efficient manner. The...

There is a trend in the power industry for high temperature components (such as steam pipe work) to be operated in an increasingly arduous fashion. This would involve the use of elevated steam temperatures/pressures and a greater frequency of start up/shut down cycles. Such generation strategies are being adopted due to the need for thermally effic...

A service-aged P91 steel was used to perform an experimental program of cyclic mechanical testing in the temperature range of 400 C-600 C, under isothermal conditions, using both saw-tooth and dwell (inclusion of a constant strain dwell period at the maximum (tensile) strain within the cycle) waveforms. The results of this testing were used to iden...

A procedure to estimate material constants for the unified Chaboche viscoplasticity model from experimental data has been published elsewhere;1. Tong J., Zhan J.L. and Vermeulen B.: Int. J. Fatigue, 2004, 26, (8), 829–837.View all references2. Gong Y.P., Hyde C.J., Sun W. and Hyde T.H.: PI Mech. Eng. L.-J. Mater., 2010, 224, (L1), 19–29.View all re...

In many situations where the characterisation of the mechanical behaviour of a specific material is required, source material for manufacture of conventional test specimens may be at a premium. Examples include the validation of new alloys for use in the power industry, the description of the heat affected zone (HAZ) of weldments1 or performing a r...

Small specimen testing techniques are potentially highly useful procedures which could be used to determine many fundamental material properties from relatively small amounts of sample material. Small specimens can be manufactured from scoop samples taken from the surface of a component, allowing for continued operation after sampling. In the past,...

Determining representative material constant sets for models that can accurately predict the complex plasticity and creep behaviour of components undergoing cyclic loading is of great interest to many industries. The Chaboche unified visco-plasticity model is an example of a model that, with the correct modifications, shows much promise for this pa...

The accurate prediction of creep life is of great importance for the structural integrity of high temperature components, such as those used in power generation plant, if safe, efficient and economically responsible operation is to be achieved. Continuum damage mechanics can be used in conjunction with finite element analysis to provide a fundament...

It may be inevitable in the design and analysis of most high temperature components (such as power industry pipe work) that variations in load and/or temperature will occur in normal operation. This presents complications in the prediction of the response of such components due to potential hardening or softening effects caused by the accumulation...

Pipe bends represent geometric discontinuities in the steam pipe systems of power plants, therefore understanding the behaviour of these potential locations of weakness is of great industrial importance for component inspection, design and analysis. Due to the high operating temperatures encountered, the failure mechanism of creep is a justified co...

Pipe bends are regions of geometric discontinuities in the pipe systems used in power plants and most industry recorded failures have been located around similar regions. Understanding these potential locations of weakness is therefore of great interest for the safe and economic operation of piping components. Increased predictive accuracy would as...

A service-aged P91 steel was used to perform an experimental programme of cyclic mechanical testing in the temperature range of 400°C to 600°C, under isothermal conditions, using both saw-tooth and dwell (inclusion of a constant strain dwell period at the maximum (tensile) strain within the cycle) waveforms. The results of this testing were used to...