Wigdan Kisha - Academia.edu (original) (raw)
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Papers by Wigdan Kisha
Advances in Heat Transfer and Thermal Engineering, 2021
In a travelling wave thermoacoustic engine, the regenerator is the heart of the engine [1], where... more In a travelling wave thermoacoustic engine, the regenerator is the heart of the engine [1], where the thermal interaction between the working gas and the solid material takes place. Unlike the stack in standing wave engine, the regenerator is more of a solid porous material which offers an advantage of better heat transfer and exhibits an enhanced performance. At the frequency of interest, excellent thermal contact can be achieved by having a regenerator of very narrow channels.
Sustainable Energy Technologies and Assessments, 2022
Incorporating thermoacoustic engines (TAEs) into clean cooking stoves offers to reduce rural ener... more Incorporating thermoacoustic engines (TAEs) into clean cooking stoves offers to reduce rural energy poverty while cutting morbidity associated with smoke inhalation. TAEs are used to generate electricity from the waste heat of a cooking fire to provide power for lighting and personal devices. This study investigated the effect of TAE mean pressure using a numerical model of a twin-core, asymmetrically heated TAE. Automation code was developed to allow the numerical model to be optimised using the Nelder-Mead algorithm to maximise electrical power output at each mean pressure. The parameters available for optimisation were the length and position of two side volumes (stubs). A maximum electrical output of 59.63 W was determined at 2.2 bar mean pressure. This is a 90% increase on the original numerical model at atmospheric pressure. Simulation-based optimisation, as performed in this study, is identified as being universally applicable to the design of TAEs
Energy, 2021
A double-core travelling-wave thermoacoustic engine was modelled and tested. • A novel operationa... more A double-core travelling-wave thermoacoustic engine was modelled and tested. • A novel operational methodology was proposed for heat addition into the two cores • Using lower heat input in the first core increased the power output by 39%. • Validation of DeltaEC models is done by comparisons with experiments.
This article describes a novel design and construction of a helical tube flash boiler that uses a... more This article describes a novel design and construction of a helical tube flash boiler that uses a 2kW nominal methylated spirit burner to heat an approximately 2.5m long coil of copper pipe fed by a nominal 8 bar electrically operated solenoid water pump. The final embodiment is for superheated steam to be converted to electricity and the waste exit heat from the generator used either for cooking or for ethanol pro duction for low-income families in developing countries. The performance of the flash boiler has been evaluated experimentally based on the well-known “Direct-Method”; by carefully measuring both the flow of the fuel and the steam. It found that the pressure inside the pipe can reach up to 7.4 bar and the temperature of the steam released by the flashing process can reach 255°C utilising a low-cost water pump. The research results prese nted in this paper demonstrate that flash boiler stove has a great potential for generating high-temperature steam for developing a low-c...
Advances in Heat Transfer and Thermal Engineering, 2021
In a travelling wave thermoacoustic engine, the regenerator is the heart of the engine [1], where... more In a travelling wave thermoacoustic engine, the regenerator is the heart of the engine [1], where the thermal interaction between the working gas and the solid material takes place. Unlike the stack in standing wave engine, the regenerator is more of a solid porous material which offers an advantage of better heat transfer and exhibits an enhanced performance. At the frequency of interest, excellent thermal contact can be achieved by having a regenerator of very narrow channels.
Sustainable Energy Technologies and Assessments, 2022
Incorporating thermoacoustic engines (TAEs) into clean cooking stoves offers to reduce rural ener... more Incorporating thermoacoustic engines (TAEs) into clean cooking stoves offers to reduce rural energy poverty while cutting morbidity associated with smoke inhalation. TAEs are used to generate electricity from the waste heat of a cooking fire to provide power for lighting and personal devices. This study investigated the effect of TAE mean pressure using a numerical model of a twin-core, asymmetrically heated TAE. Automation code was developed to allow the numerical model to be optimised using the Nelder-Mead algorithm to maximise electrical power output at each mean pressure. The parameters available for optimisation were the length and position of two side volumes (stubs). A maximum electrical output of 59.63 W was determined at 2.2 bar mean pressure. This is a 90% increase on the original numerical model at atmospheric pressure. Simulation-based optimisation, as performed in this study, is identified as being universally applicable to the design of TAEs
Energy, 2021
A double-core travelling-wave thermoacoustic engine was modelled and tested. • A novel operationa... more A double-core travelling-wave thermoacoustic engine was modelled and tested. • A novel operational methodology was proposed for heat addition into the two cores • Using lower heat input in the first core increased the power output by 39%. • Validation of DeltaEC models is done by comparisons with experiments.
This article describes a novel design and construction of a helical tube flash boiler that uses a... more This article describes a novel design and construction of a helical tube flash boiler that uses a 2kW nominal methylated spirit burner to heat an approximately 2.5m long coil of copper pipe fed by a nominal 8 bar electrically operated solenoid water pump. The final embodiment is for superheated steam to be converted to electricity and the waste exit heat from the generator used either for cooking or for ethanol pro duction for low-income families in developing countries. The performance of the flash boiler has been evaluated experimentally based on the well-known “Direct-Method”; by carefully measuring both the flow of the fuel and the steam. It found that the pressure inside the pipe can reach up to 7.4 bar and the temperature of the steam released by the flashing process can reach 255°C utilising a low-cost water pump. The research results prese nted in this paper demonstrate that flash boiler stove has a great potential for generating high-temperature steam for developing a low-c...