Preliminary design of a supercritical CO2 wind tunnel

Abstract In recent years, supercritical CO2 (sCO2) Brayton cycles have drawn the attention of researchers due to their high cycle efficiencies, compact turbomachinery, and environmental friendliness. For small-scale cycles, radial inflow turbines (RIT) are the prevailing choice and one of the key components. A mean line design procedure for sCO2 RIT is developed and design space exploration conducted for a 100 kW-class turbine for a low-temperature waste-heat utilization sCO2 Brayton cycle. By varying the two design parameters, specific speed and velocity ratio, different turbine configurations are setup and compared numerically by means of computational fluid dynamics (CFD) simulations. Results are analyzed to conclude on optimum design parameters with regard to turbine efficiency and expansion ratio. Specific speeds between 0.2 and 0.5 are recommended for sCO2 RIT with small though flow (3 kg/s). The higher the velocity ratio, the bigger the turbine expansion ratio. Pairs of optimum design parameters that effectuate maximum efficiency are identified, with smaller velocity ratios prevailing for smaller specific speeds. The turbine simulation results for sCO2 are compared to well-established recommendations for the design of RIT from literature, such as the Balje diagram. It is concluded that for the design of sCO2 RITs, the same principles can be used as for those for air turbines. By achieving total-to-static stage and rotor efficiencies of 84% and 86%, respectively, the developed mean line design procedure has proven to be an effective and easily applicable tool for the preliminary design of small-scale sCO2 RIT.

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Preliminary Design Study of Supercritical CO2 Cycle for Small Modular Reactor Application

10.13182/t31081 ◽

2019 ◽

Author(s):

Y. Ahn ◽

Y. Yoo

Keyword(s):

Supercritical Co2 ◽

Preliminary Design ◽

Design Study ◽

Small Modular Reactor ◽

Reactor Application

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A CFD Simulation of Coal Syngas Oxy-Combustion in a High-Pressure Supercritical CO2 Environment

Volume 4A: Combustion, Fuels and Emissions ◽

10.1115/gt2017-63821 ◽

2017 ◽

Author(s):

Hassan Abdul-Sater ◽

James Lenertz ◽

Chris Bonilha ◽

Xijia Lu ◽

Jeremy Fetvedt

Keyword(s):

Conceptual Design ◽

Supercritical Co2 ◽

Numerical Study ◽

Process Models ◽

Preliminary Design ◽

Coal Syngas ◽

Complete Combustion ◽

Flow Rates ◽

Power Cycle ◽

The Impact

The Allam Cycle is an oxy-fuel supercritical CO2 power cycle that generates low-cost electricity from fossil fuels while producing near-zero air emissions. The turbine exhaust (sCO2) is then available for partial injection into underground storage while remainder is reused in the power cycle. Novel combustors required by this and other sCO2 cycles are critical to their commercialization. A conceptual design was developed for a coal syngas-fueled oxy-fuel combustor that meets the conditions of the Allam Cycle. The design of this combustor utilizes a 300MWe coal syngas-fired Allam Cycle thermodynamic analyses and ASPEN process models as inputs to the combustor. The primary inputs for design of the combustor included the fuel mixture compositions and respective flow rates for the constituent gases, pressures, and operating temperatures which were scaled to a 5MWth test article. The combustor was sized to accommodate the required pressures, heat release rate, flow rates, and residence times to produce well mixed turbine inlet flows with complete combustion. A preliminary design for a 5MWth test scale combustor was then developed, and a numerical study using Computational Fluid Dynamics (CFD) simulations was carried out to demonstrate the feasibility of that combustor. Steady-state RANS simulations were used to qualitatively examine the preliminary design of the 5MWth combustor and predict the fluid mechanics, heat transfer, and combustion. The purpose of the analysis was to verify the following criteria: 1) good mixing of the fuel and oxidizer in the primary zone, 2) uniform exhaust gas temperature and 3) efficient combustion with complete CO burnout. Additionally, the analysis investigated wall temperature and the impact of varying the fuel composition on combustion performance. The CFD model results were in good agreement with the equilibrium one-dimensional (1D) Aspen model results. The CFD predictions of the current conceptual design verified the identified key criteria for the combustor and demonstrated its feasibility.

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Preliminary Design of a LSA Aircraft Using Wind Tunnel Tests

INCAS BULLETIN ◽

10.13111/2066-8201.2015.7.4.3 ◽

2015 ◽

Vol 7 (4) ◽

pp. 33-39 ◽

Cited By ~ 2

Author(s):

ANGI Norbert ◽

◽

HUMINIC Angel ◽

Keyword(s):

Wind Tunnel ◽

Preliminary Design ◽

Wind Tunnel Tests

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Analysis and Preliminary Design of a Sailboat with Self-Trimming Wing Sail

Marine Technology and SNAME News ◽

10.5957/mt1.1983.20.4.370 ◽

1983 ◽

Vol 20 (04) ◽

pp. 370-376

Author(s):

B. G. Newman ◽

G. I. Fekete

Keyword(s):

Reynolds Number ◽

Wind Tunnel ◽

Preliminary Design ◽

Static And Dynamic Stability ◽

Flap Deflection ◽

The Stability ◽

Lift And Drag ◽

Existing Data ◽

Good Agreement ◽

Rigid Wing

A theoretical analysis has been made of the static and dynamic stability of a self-trimming rigid wing sail for use on a sailboat without sheets or halyards. The effects of camber or flap deflection and the position of the trimming plane are considered. A satisfactory design incorporates an uncambered main wing of medium aspect ratio and a trimming tail plane. Wind tunnel tests on a model of this design confirmed the stability of the sail and indicated adequate damping. The measured lift and drag coefficients were in good agreement with existing data at a similar Reynolds number.

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A Code for the Preliminary Design of Cooled Supercritical CO2 Turbines and Application to the Allam Cycle

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4052146 ◽

2021 ◽

Author(s):

Roberto Scaccabarozzi ◽

Emanuele Martelli ◽

Matteo Pini ◽

Carlo De Servi ◽

Paolo Chiesa ◽

...

Keyword(s):

Film Cooling ◽

Gas Turbines ◽

Supercritical Co2 ◽

Fluid Dynamic ◽

Thermal Design ◽

Working Fluid ◽

Preliminary Design ◽

Turbine Efficiency ◽

Multi Stage ◽

Axial Turbines

Abstract This paper documents a thermo-fluid-dynamic mean-line model for the preliminary design of multi-stage axial turbines with blade cooling applicable to supercritical CO2 turbines. Given the working fluid and coolant inlet thermodynamic conditions, blade geometry, number of stages and load criterion, the model computes the stage-by-stage design along with the cooling requirement and ultimately provides an estimate of turbine efficiency via a semi-empirical loss model. Different cooling modes are available and can be selected by the user (stand-alone or combination): convective cooling, film cooling, thermal barrier coating. The model is applied to attain the preliminary aero-thermal design of the 600 MW cooled axial supercritical CO2 turbine of the Allam cycle. Results show that a load coefficient varying from 3 to 1 throughout the machine, and a reaction degree ranging from 0.1 to 0.5 lead to the maximum total-to-static turbine efficiency of about 85 %. Consequently, as opposed to uncooled CO2 turbines, a repeated stage configuration is an unsuited design choice for cooled sCO2 machines. Moreover, the study highlights that film cooling is considerably less effective compared to conventional gas turbines, while increasing the number of stages from 5 to 6 and adopting higher rotational speeds leads to an increased efficiency.

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Multidisciplinary Assessment of the Control of the Propellers of a Pusher Geared Open Rotor—Part I: Zero-Dimensional Performance Model for Counter-Rotating Propellers

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4032008 ◽

2016 ◽

Vol 138 (7) ◽

Cited By ~ 3

Author(s):

Pablo Bellocq ◽

Inaki Garmendia ◽

Vishal Sethi ◽

Alexis Patin ◽

Stefano Capodanno ◽

...

Keyword(s):

Wind Tunnel ◽

Fuel Consumption ◽

Test Data ◽

Wind Tunnel Test ◽

Performance Model ◽

Preliminary Design ◽

Open Rotor ◽

And Control ◽

The Impact ◽

A Performance

Due to their high propulsive efficiency, counter-rotating open rotors (CRORs) have the potential to significantly reduce fuel consumption and emissions relative to conventional high bypass ratio turbofans. However, this novel engine architecture presents many design and operational challenges both at engine and aircraft level. The assessment of the impact of the main low-pressure preliminary design and control parameters of CRORs on mission fuel burn, certification noise, and emissions is necessary at preliminary design stages in order to identify optimum design regions. These assessments may also aid the development process when compromises need to be performed as a consequence of design, operational, or regulatory constraints. The required preliminary design simulation tools should ideally be 0D or 1D (for computational purposes) and should capture the impact of the independent variation of the main low-pressure system design and control variables, such as the number of blades, diameter and rotational speed of each propeller, the spacing between the propellers, and the torque ratio (TR) of the gearbox or the counter-rotating turbine (CRT), among others. From a performance point of view, counter-rotating propellers (CRPs) have historically been modeled as single propellers. Such a performance model does not provide the required flexibility for a detailed design and control study. Part I of this two-part publication presents a novel 0D performance model for CRPs allowing an independent definition of the design and operation of each of the propellers. It is based on the classical low-speed performance model for individual propellers, the interactions between them, and a compressibility correction which is applied to both propellers. The proposed model was verified with publicly available wind tunnel test data from NASA and was judged to be suitable for preliminary design studies of geared and direct drive open rotors. The model has to be further verified with high-speed wind tunnel test data of highly loaded propellers, which was not found in the public domain. In Part II, the novel CRP model is used to produce a performance model of a geared open rotor (GOR) engine with a 10% clipped propeller designed for a 160 PAX and 5700 NM aircraft. This engine model is first used to study the impact of the control of the propellers on the engine specific fuel consumption (SFC). Subsequently, it was integrated in a multidisciplinary simulation platform to study the impact of the control of the propellers on engine weight, certification noise, and NOx emission.

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