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Iterative operation point determination of an automotive turbocharger-derived micro gas turbine using manufacturer compressor maps and CFD-based turbine modeling
(2026-03-01)
Suksam, Niwat
;
Onthong, Kasemsil
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Laosuwan, Songtam
;
Oo, Aung Htet
;
Wasinarom, Kittipass
Microturbine power systems comprise a wide range of thermodynamic components, and the accuracy of system-level performance simulations strongly depends on reliable prediction of the coupled compressor–turbine operating characteristics. Unlike conventional approaches that rely on empirical matching between specific compressors and turbines, this study proposes a novel physics-based iterative method for determining steady-state operating points of automotive turbocharger–derived micro gas turbines. The method couples manufacturer-provided compressor performance maps with turbine characteristics obtained from computational fluid dynamics (CFD) simulations. Consistency in mass flow rate, pressure ratio, and rotational speed is enforced iteratively to predict steady-state thermodynamic parameters over a wide range of shaft speeds. The proposed methodology is demonstrated using a commercially available automotive turbocharger operating at shaft speeds between 80,000 and 170,000 rpm. CFD analysis provides insight into turbine irreversibilities, including viscous and kinetic energy losses. Experimental validation under self-sustained, no-load operating conditions shows good agreement with predicted results, with deviations of all major thermal parameters remaining below 6 % at a representative pressure ratio of 2.5, thereby confirming the reliability of the proposed approach. Furthermore, the applicability of the predicted operating envelope to a recuperated micro gas turbine cycle is evaluated. The results indicate a peak thermal efficiency of approximately 19 % at shaft speeds between 130,000 and 170,000 rpm and pressure ratios ranging from 2.0 to 2.94. Overall, the proposed operating-point determination method provides a practical, accurate, and reusable tool for performance assessment and design optimization of microturbine-based energy systems under various configurations.
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Thermal Behavior of Biomass under Thermochemical Treatment at Different Air Fluxes in an Updraft Reactor
(2023-05-01)
Wasinarom, Kittipass
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Sungworagarn, Sarawut
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Sathitruangsak, Prasan
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Singmai, Wichean
;
Onthong, Kasemsil
Thermochemical treatment was investigated experimentally at different air fluxes in an updraft reactor. The test rig was equipped with a special attached door that will open at a specific time step. This unique feature allows investigators to obtain information on the packed bed color variation along the different heights of the reactor that evolves at different points in time. The analysis focused on the temperature dynamics obtained from installed thermocouples with the packed bed color variation at each time step. The investigation was conducted for three different supply air mass fluxes, which were 670, 480, and 190 kg/m<sup>2</sup>h. The general thermal behavior is addressed in the first part of the paper because it is similar for all different input air mass fluxes. Next, the distinctive operation parameters among different air mass fluxes are discussed; these included the hot spot zone, fuel conversion characteristic, temperature distribution, heat transfer, and kinetic activities along the height of the reactor.
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Improvement of Discharge Flow Structure by Bluff-Body Insert and Size Reduction of a Mixed-Flow Irrigation Pump
(2022-03-01)
Wasinarom, Kittipass
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Boonchauy, Dachdanai
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Noosomton, Jaruphant
;
Charoensuk, Jarruwat
This paper concerns efficiency improvement of an 8-in. mixed-flow irrigation pump by modification of discharge flow channel. First, computational fluid dynamics (CFD) modeling was validated with the experimental results using an available pump. Next, an investigation on the hydrodynamics structure was carried out by CFD. The investigation revealed large recirculation around the inner annulus area next to the impeller exit plane and jet flow around the pipe wall. This leads to formation of a strong shear layer between jet and recirculation flow. Improvements were realized by reducing the impeller size by 10% to increase the flow cross-sectional area between the impeller exit plane and the tube wall to slow down the jet flow. Bluff body was introduced at the inner annulus adjacent to the discharge flow channel to alleviate a recirculation wake region. The operating speed of the scaled-down impeller was increased from 900 to 1,100 rpm to compensate for the scaling effect, and the blade angle was modified to cope with the change of inlet relative flow angle. Experimental study suggested that more than 10% improvement could be achieved through these modifications. The maximum efficiency of the proposed model was 42%, compared with the maximum efficiency of 37% for the conventional model.
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Formation of multiple combustion fronts in an imbert downdraft gasification reactor
(2021-09-10)
Wasinarom, Kittipass
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Sungworagarn, Sarawut
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Sathitruangsak, Prasan
;
Onthong, Kasemsil
The experimental study of downdraft gasification was performed in this paper. The operation which led to the formation of the second combustion front was pointed out. In this situation, both combustion fronts will lose their intensity and finally be extinguished. The operation was unintentionally stopped. It was revealed that the combustion front propagated upward in the reactor after starting the test. While it was about to reach the air inlet nozzle, the second combustion front was detected by an abrupt temperature rise of the thermocouple above the air supply nozzle. After the formation of the second combustion front, both fronts started to lose their intensity which indicated by the decrease in temperature corresponding with their locations. It was possible that the second combustion front would dilute the oxygen concentration supplied to the first combustion front. The decreasing temperature of the first combustion front reduced the heat transfer rate to the second combustion front. Finally, both combustion fronts were extinguished. The operation was unintentionally stopped.
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CFD based Improvement of Thai Irrigation Pump
(2020-08-31)
Wasinarom, Kittipass
;
Boonchauy, Dachdanai
;
Charoensuk, Jarruwat
Evaluation phase which was partial fulfilment of the beginning phase of "Development of Performance test rig and Efficiency improvement of impeller in Thai irrigation pump project" is presented in this paper. Overall flow field in the pump system that consisted of inlet, impeller and stator vane of the available pump was analyzed using commercial Computational Fluid Dynamics (CFD) code. The goal of this investigation is to obtain more understanding of energy dissipation which results from shear stress that developed within the flow field in each section of the pump. The improvement measure is then conducted with the concern of manufacturing difficulties. High dissipation flow structure was observed around the impeller outlet. Jet-wake and recirculation flow were observed. The first improvement measure was conducted by adding the bluff body in the flow channel to alleviate jet-wake structure and delay flow separation. After the implementation of the optimized bluff body around the impeller exit, CFD results indicated around 3-8% improvement compared with the CFD results of the available pump for the entire range of operating conditions.
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CFD based Improvement of Thai Irrigation Pump
(2020-01-01)
Wasinarom, Kittipass
;
Boonchauy, Dachdanai
;
Charoensuk, Jarruwat
Evaluation phase which was partial fulfilment of the beginning phase of "Development of Performance test rig and Efficiency improvement of impeller in Thai irrigation pump project" is presented in this paper. Overall flow field in the pump system that consisted of inlet, impeller and stator vane of the available pump was analyzed using commercial Computational Fluid Dynamics (CFD) code. The goal of this investigation is to obtain more understanding of energy dissipation which results from shear stress that developed within the flow field in each section of the pump. The improvement measure is then conducted with the concern of manufacturing difficulties. High dissipation flow structure was observed around the impeller outlet. Jet-wake and recirculation flow were observed. The first improvement measure was conducted by adding the bluff body in the flow channel to alleviate jet-wake structure and delay flow separation. After the implementation of the optimized bluff body around the impeller exit, CFD results indicated around 3-8% improvement compared with the CFD results of the available pump for the entire range of operating conditions.

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