Numerical and Experimental Investigation of a Low Order Radial Turbine Model for Engine-Level Optimisation of Turbocharger Design

Author(s):  
Karl Georg Hohenberg ◽  
Ricardo F. Martinez-Botas ◽  
Piotr Luczynski ◽  
Carola Freytag ◽  
Manfred Wirsum

Abstract This paper presents the development and validation of a meanline model by means of numerical and experimental methods, to determine it's feasibility as an optimisation tool for turbocharger matching. Using a parametric turbine model, numerical experiments were conducted accounting for variations of several key turbine design parameters and a wide operating range. The resulting dataset was used to test the accuracy of the meanline model when calibrated to a baseline design and thus evaluate it's ability of extrapolating to different designs. The loss models were examined in more detail, and a set of loss models which provided the most accurate results is presented. The meanline model was further validated experimentally using dynamometer test results of 6 turbine designs from the same parametric turbine model. The result showed that for design point and high power operation, an error of less than 3.1% and 2.0% was achieved for efficiency and mass flow parameter respectively. This led to the conclusion that the model would be sufficiently accurate to represent design changes relevant to turbocharger matching

Author(s):  
Karl Hohenberg ◽  
Ricardo Martinez-Botas ◽  
Piotr Łuczyński ◽  
Carola Freytag ◽  
Manfred Wirsum

Abstract This paper presents the development and validation of a meanline model by means of numerical and experimental methods, to determine it’s feasibility as an optimisation tool for turbocharger matching. Using a parametric turbine model, numerical experiments were conducted accounting for variations of several key turbine design parameters and a wide operating range. The resulting dataset was used to test the accuracy of the meanline model when calibrated to a baseline design and thus evaluate it’s ability of extrapolating to different designs. The loss models were examined in more detail, and a set of loss models which provided the most accurate results is presented. The meanline model was further validated experimentally using dynamometer test results of 6 turbine designs from the same parametric turbine model. The result showed that for design point and high power operation, an error of less than 3.1% and 2.0% was achieved for efficiency and mass flow parameter respectively. This led to the conclusion that the model would be sufficiently accurate to represent design changes relevant to turbocharger matching.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 674
Author(s):  
Paul Caicedo ◽  
David Wood ◽  
Craig Johansen

Solar chimney power plants (SCPPs) collect air heated over a large area on the ground and exhaust it through a turbine or turbines located near the base of a tall chimney to produce renewable electricity. SCPP design in practice is likely to be specific to the site and of variable size, both of which require a purpose-built turbine. If SCPP turbines cannot be mass produced, unlike wind turbines, for example, they should be as cheap as possible to manufacture as their design changes. It is argued that a radial inflow turbine with blades made from metal sheets, or similar material, is likely to achieve this objective. This turbine type has not previously been considered for SCPPs. This article presents the design of a radial turbine to be placed hypothetically at the bottom of the Manzanares SCPP, the only large prototype to be built. Three-dimensional computational fluid dynamics (CFD) simulations were used to assess the turbine’s performance when installed in the SCPP. Multiple reference frames with the renormalization group k-ε turbulence model, and a discrete ordinates non-gray radiation model were used in the CFD simulations. Three radial turbines were designed and simulated. The largest power output was 77.7 kW at a shaft speed of 15 rpm for a solar radiation of 850 W/m2 which exceeds by more than 40 kW the original axial turbine used in Manzanares. Further, the efficiency of this turbine matches the highest efficiency of competing turbine designs in the literature.


1977 ◽  
Vol 99 (3) ◽  
pp. 567-577
Author(s):  
S. Chacour ◽  
J. E. Graybill

“IRIS” is a computerized design and structural optimization system capable of generating all the major hydraulic and mechanical design parameters of high head pump/turbines from limited input data. The program will size the unit and select the proper hydraulic passage configuration according to performance requirements and optimize the dimensions of all the major components, generate command tapes used by a numerically controlled flame cutter, estimate cost, and issue manufacturing process planning. It also generates finite element models for the “in depth” analysis of critical components.


Author(s):  
Yiming Ma ◽  
Liusheng He ◽  
Ming Li

Steel slit shear walls (SSSWs), made by cutting slits in steel plates, are increasingly adopted in seismic design of buildings for energy dissipation. This paper estimates the seismic energy dissipation capacity of SSSWs considering out-of-plane buckling. In the experimental study, three SSSW specimens were designed with different width-thickness ratios and aspect ratios and tested under quasi-static cyclic loading. Test results showed that the width-thickness ratio of the links dominated the occurrence of out-of-plane buckling, which produced pinching in the hysteresis and thus reduced the energy dissipation capacity. Out-of-plane buckling occurred earlier for the links with a larger width-thickness ratio, and vice versa. Refined finite element model was built for the SSSW specimens, and validated by the test results. The concept of average pinching parameter was proposed to quantify the degree of pinching in the hysteresis. Through the parametric analysis, an equation was derived to estimate the average pinching parameter of the SSSWs with different design parameters. A new method for estimating the energy dissipation of the SSSWs considering out-of-plane buckling was proposed, by which the predicted energy dissipation agreed well with the test results.


Author(s):  
H. R. Born

This paper presents an overview of the development of a reliable bearing system for a new line of small turbochargers where the bearing system has to be compatible with a new compressor and turbine design. The first part demonstrates how the increased weight of the turbine, due to a 40 % increase in flow capacity, influences the dynamic stability of the rotor-bearing system. The second part shows how stability can be improved by optimizing important floating ring parameters and by applying different bearing designs, such as profiled bore bearings supported on squeeze film dampers. Test results and stability analyses are included as well as the criteria which led to the decision to choose a squeeze film backed symmetrical 3-lobe bearing for this new turbocharger design.


Author(s):  
Carlo Cravero ◽  
Martino Marini

The authors decided to organize their design/analysis computational tools in an integrated software suite in order to help teaching radial turbine, taking advantage of their research background and a set of codes previously developed. The software is proposed for use during class works and the student can either use a single design/analysis tool or face a complete design loop consisting of iterations between design and analysis tools. The intended users are final year students in mechanical engineering. The codes output are discussed with two practical examples in order to highlight the turbomachinery performance at design and off-design conditions. The above suite gives the student the opportunity of getting used to different concepts (choking, blade loading, performance maps, …) that are encountered in turbomachinery design and of understanding the effects of the main design parameters.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chansik An ◽  
Hyun Cheol Oh ◽  
Jung Hyun Chang ◽  
Seung-Jin Oh ◽  
Jung Mo Lee ◽  
...  

AbstractWe developed a tool to guide decision-making for early triage of COVID-19 patients based on a predicted prognosis, using a Korean national cohort of 5,596 patients, and validated the developed tool with an external cohort of 445 patients treated in a single institution. Predictors chosen for our model were older age, male sex, subjective fever, dyspnea, altered consciousness, temperature ≥ 37.5 °C, heart rate ≥ 100 bpm, systolic blood pressure ≥ 160 mmHg, diabetes mellitus, heart disease, chronic kidney disease, cancer, dementia, anemia, leukocytosis, lymphocytopenia, and thrombocytopenia. In the external validation, when age, sex, symptoms, and underlying disease were used as predictors, the AUC used as an evaluation metric for our model’s performance was 0.850 in predicting whether a patient will require at least oxygen therapy and 0.833 in predicting whether a patient will need critical care or die from COVID-19. The AUCs improved to 0.871 and 0.864, respectively, when additional information on vital signs and blood test results were also used. In contrast, the protocols currently recommended in Korea showed AUCs less than 0.75. An application for calculating the prognostic score in COVID-19 patients based on the results of this study is presented on our website (https://nhimc.shinyapps.io/ih-psc/), where the results of the validation ongoing in our institution are periodically updated.


2021 ◽  
pp. 1-30
Author(s):  
Alejandro Castillo Pardo ◽  
Cesare A. Hall

Abstract Boundary Layer Ingestion (BLI) potentially offers significant reductions in fuel burn and pollutant emissions. The Propulsive Fuselage Concept features a fan at the back of the airframe that ingests the 360deg fuselage boundary layer. Consequently, the distortion at the fan face during cruise is close to radial. This paper aims to devise and test a fan design philosophy that is tuned to this inflow distortion. Initially a free-vortex fan design matched to clean inflow is presented. The effects of BLI on the aerodynamics of this fan are investigated. A series of design steps are then presented to develop the baseline fan into a new design matched to fuselage BLI inflow. Both fan designs have been tested within a low speed rig. The impact of the fan design changes on the aerodynamics and the performance with BLI are evaluated using the test results. This paper presents the successful application of a unique experimental facility for the analysis of BLI fuselage fans. It shows that it is possible to design a fan that accepts the radial distortion caused by fuselage BLI with a modified profile of work input. The new fan design was found to increase the work input by 4.9% and to improve the efficiency by 2.75% relative to a fan designed for clean flow. This new fan design has reduced loading near the hub to account for the incoming distortion, increased mid span loading and negative incidence towards the tip for tolerance to circumferential distortion off-design.


Author(s):  
Jaegon Yoo ◽  
Koo-Tae Kang ◽  
Jin-Wook Huh ◽  
Chimahn Choi

Since gear noise in automotive is one of the most unpleasant noises for passengers, various solutions, such as gear design optimization, tooth modification and transfer path reformations in the vehicle have been developed. But, these attempts are mainly focused on the fundamental mesh excitation of the gear set without any consideration of their harmonic noise (1st, 2nd or higher). Harmonic gear whine noise is easily audible in the vehicle because of their high frequency characteristics in spite of low sound pressure level. This annoying pure-tone noise is usually issued in the transmission system composed of the gears produced by grinding process. This paper will present the main sources of this harmonic gear whine noise with the test results of gears with identical design parameters but having different surface structure (roughness parameters, wave patterns). Additionally, manufacturing guidelines of gear surface structure will be proposed at the end of this paper.


Author(s):  
Ebrahim Mazharsolook ◽  
David C. Robinson ◽  
Jonathan D. Casey

Abstract Statistical methods are explored for the use in modelling of discrete manufacturing. The developed methodologies based on Design of Experiments (DOE) and stepwise regression to obtain the product model are described. This model is then embedded within a software system which is used for simulation of design changes, process changes and disturbances. The software is used to predict final test results in respect of up-stream parameter changes. A case study is presented o show the implementation of this method of modelling in Quality Control of manufacture. This case study has successfully been implemented. The system is currently assisting the company in design of similar product. Feasibility of applying Artificial Intelligen (AI) techniques to Model-Based Quality Control (MBQC) is investigated. An outline of the future development of Hybrid MBQC is then presented.


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