CFD Analysis and Full Scale Testing of a Complex Auxiliary Power Unit Intake System

2011 ◽  
Author(s):  
Bruce Bouldin ◽  
Kiran Vunnam ◽  
Jose-Angel Hernanz-Manrique ◽  
Laura Ambit-Marin
Keyword(s):  
Large Scale ◽  
Cooling System ◽  
Full Scale ◽  
Cfd Analysis ◽  
Flow Distortion ◽  
Pressure Losses ◽  
Intake System ◽  
Auxiliary Power ◽  
Engine Compressor ◽  
The Impact

Auxiliary Power Units (APU’s) are gas turbine engines which are located in the tail of most commercial and business aircraft. They are designed to provide electrical and pneumatic power to the aircraft on the ground while the main propulsion engines are turned off. They can also be operated in flight, when there is a desire to reduce the load on the propulsion engines, such as during an engine-out situation. Given an APU’s typical position in the back of an airplane, the intake systems for APU’s can be very complex. They are designed to provide sufficient airflow to both the APU and the cooling system while minimizing the pressure losses and the flow distortion. These systems must perform efficiently during static operation on the ground and during flight at very high altitudes and flight speeds. An APU intake system has been designed for a new commercial aircraft. This intake system was designed using the latest Computational Fluid Dynamics (CFD) techniques. Several iterations were performed between the APU supplier and the aircraft manufacturer since each of their components affects the performance of the other. For example, the aircraft boundary layer impacts APU intake performance and an open APU flap impacts aircraft drag. To validate the effectiveness of the CFD analysis, a full scale intake rig was designed and built to simulate the tailcone of the aircraft on the ground. This rig was very large and very detailed. It included a portion of the tailcone and rudder, plus the entire APU and cooling intake systems. The hardware was manufactured out of fiberglass shells, stereolithogrophy components and machined plastic parts. Three different airflows for the load compressor, engine compressor and cooling system had to be measured and throttled. Fixed instrumentation rakes were located to measure intake induced pressure losses and distortion at the APU plenum and cooling ducts. Rotating pressure and swirl survey rakes were located at the load compressor and engine compressor eyes to measure plenum pressure losses and distortion. Static pressure taps measured the flow pattern along the intake and flap surfaces. The intake rig was designed to be flexible so that the impact of rudder position, intake flap position, APU plenum baffle position and compressor airflow levels could be evaluated. This paper describes in detail the different components of the intake rig and discusses the complexity of conducting a rig test on such a large scale. It also presents the impact of the different component positions on intake performance. These results were compared to CFD predicted values and were used to calibrate our CFD techniques. The effectiveness of using CFD for APU intake design and its limitations are also discussed.

The Use of 3D CFD Analysis in the Design of Air Intake Systems as a Visualisation Tool to Optimise Performance in Gas Turbine Applications

2005 ◽  
Author(s):  
Stephen D. Hiner
Keyword(s):  
Gas Turbine ◽  
Case Studies ◽  
Cfd Analysis ◽  
Flow Distortion ◽  
Inlet System ◽  
Pressure Losses ◽  
Intake System ◽  
Air Intake ◽  
Flow Through ◽  
The Impact

An optimised inlet air system design is an important factor in the gas turbine (GT) industry. Optimising the design of the air intake system is an increasingly challenging process as both the layout complexity and range of features that can be included in the intake system expands. These may include a combination of insect or trash screens, weather protection and filtration systems, silencers, anti-icing systems, ventilation system off takes and inlet heating or cooling systems for power augmentation. Poor designs can result in inefficient use of these components as well as losses in engine performance due to excessive pressure losses or distortion in the flow entering the gas turbine. High flow distortion, velocity, pressure or temperature, can induce compressor surge and high acromechanical stresses in compressor blades and vanes. In extreme cases this may result in blade or vane failures. Computational Fluid Dynamics (CFD) analysis is a powerful tool for visualisation of the predicted flow through a hypothetical air inlet system prior to manufacture. The CFD output plots include flow streamlines and contours, of pressure, velocity or temperature, at any plane in the model. These enable pressure losses, flow distortion issues, potential recirculation areas and high local velocities within the system to be reviewed. This allows optimisation of the installation design to minimise system pressure loss and flow distortion, both through the components and at the engine interface. This paper, with reference to case studies of gas turbine applications, highlights the impact that CFD analysis can have on the design of intake systems to ensure that the best overall performance is obtained. The process of developing the CFD geometry and how significant features of an installation are modeled is outlined. Environmental and operational conditions, such as cross winds can impact the flow through an intake system; therefore, incorporation of such factors into the model boundary conditions are covered. Typical output metrics from the CFD analysis are shown from selected case studies; total pressure drop and flow distortion at the interface plane between the intake system and gas turbine. The importance of experienced interpretation of the CFD output to define potential intake design modifications to improve system performance is highlighted. In specific cases model testing has been carried out to validate CFD results. Case study examples are used to show the improvements made in air intake performance that contribute to increased operational efficiency of the gas turbine application.

Preliminary Evaluation of the 24 Ft. Diameter Fan Performance In the MinWaterCSP Large Cooling Systems Test Facility

2021 ◽  
Author(s):  
S. J. van der Spuy ◽  
D. N. J. Els ◽  
L. Tieghi ◽  
G. Delibra ◽  
A. Corsini ◽  
...  
Keyword(s):  
Scaling Laws ◽  
Static Pressure ◽  
Cooling System ◽  
Pressure Rise ◽  
Full Scale ◽  
Test Facility ◽  
Small Scale ◽  
Preliminary Evaluation ◽  
Cfd Analysis ◽  
Setting Angle

Abstract The MinWaterCSP project was defined with the aim of reducing the cooling system water consumption and auxiliary power consumption of concentrating solar power (CSP) plants. A full-scale, 24 ft (7.315 m) diameter model of the M-fan was subsequently installed in the Min WaterCSP cooling system test facility, located at Stellenbosch University. The test facility was equipped with an in-line torque arm and speed transducer to measure the power transferred to the fan rotor, as well as a set of rotating vane anemometers upstream of the fan rotor to measure the air volume flow rate passing through the fan. The measured results were compared to those obtained on the 1.542 m diameter ISO 5801 test facility using the fan scaling laws. The comparison showed that the fan power values correlated within +/− 7% to those of the small-scale fan, but at a 1° higher blade setting angle for the full-scale fan. To correlate the expected fan static pressure rise, a CFD analysis of the 24 ft (7.315 m) diameter fan installation was performed. The predicted fan static pressure rise values from the CFD analysis were compared to those measured on the 1.542 m ISO test facility, for the same fan. The simulation made use of an actuator disc model to represent the effect of the fan. The results showed that the predicted results for fan static pressure rise of the installed 24 ft (7.315 m) diameter fan correlated closely (smaller than 1% difference) to those of the 1.542 m diameter fan at its design flowrate but, once again, at approximately 1° higher blade setting angle.

New Earth-space infrastructures enable full-scale monitoring capability

2021 ◽  
Author(s):  
Eija Tanskanen ◽  
Tero Raita ◽  
Joni Tammi ◽  
Jouni Pulliainen ◽  
Hannu Koivula ◽  
...  
Keyword(s):  
Large Scale ◽  
Situational Awareness ◽  
Full Scale ◽  
The Arctic ◽  
Environment Change ◽  
Earth Space ◽  
Earth Environment ◽  
Internal Sources ◽  
Space Environments ◽  
The Impact

<p>The near-Earth environment is continuously changing by disturbances from external and internal sources. A combined research ecosystem is needed to be able to monitor short- and long-term changes and mitigate their societal effects. Observatories and large-scale infrastructures are the best way to guarantee continuous 24/7 observations and full-scale monitoring capability. Sodankylä Geophysical Observatory takes care of continuous geoenvironmental monitoring in Finland and together with national infrastructures such as FIN-EPOS and E2S enable extending and expanding the monitoring capability. European Plate Observing System of Finland (FIN-EPOS) and flexible instrument network of FIN-EPOS (FLEX-EPOS) will create a national pool of instruments including geophysical instruments targeted for solving topical questions of solid Earth physics. Scientific and new hardware building by FLEX-EPOS is essential in order to identify and reduce the impact of seismic, magnetic and geodetic hazards and understand the underlying processes.</p><p> </p><p>New national infrastructure Earth-Space Research Ecosystem (E2S) will combine measurements from atmosphere to near-Earth and distant space. This combined infrastructure will enable resolving how the Arctic environment change over the seasons, years, decades and centuries. We target our joint efforts to improve the situational awareness in the near-Earth and space environments, and in the Arctic for enhancing safety on ground and in space. This presentation will give details on the large-scale Earth-space infrastructures and research ecosystems and will give examples on how they can improve the safety of society.</p>

Introduction of Circumferentially Nonuniform Variable Guide Vanes in the Inlet Plenum of a Centrifugal Compressor for Minimum Losses and Flow Distortion

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Ismail Sezal ◽  
Nan Chen ◽  
Christian Aalburg ◽  
Rajesh Kumar V. Gadamsetty ◽  
Wolfgang Erhard ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Variable Speed ◽  
Flow Distortion ◽  
Flow Rates ◽  
Guide Vanes ◽  
Baseline Design ◽  
Pressure Losses ◽  
Operating Range ◽  
Maximum Angle ◽  
The Impact

In the oil and gas industry, large variations in flow rates are often encountered, which require compression trains with a wide operating range. If the stable operating range at constant speed is insufficient, variable speed drivers can be used to meet the requirements. Alternatively, variable inlet guide vanes (IGVs) can be introduced into the inlet plenum to provide pre- or counterswirl to the first-stage impeller, possibly eliminating the need for variable speed. This paper presents the development and validation of circumferentially nonuniform IGVs that were specifically designed to provide maximum angle variation at minimum losses and flow distortion for the downstream impeller. This includes the comparison of three concepts: a baseline design based on circumferentially uniform and symmetric profiles, two circumferentially nonuniform concepts based on uniquely cambered airfoils at each circumferential position, and a multi-airfoil configuration consisting of a uniquely cambered fixed part and a movable part. The idea behind the circumferentially nonuniform designs was to take into account nonsymmetric flow features inside the plenum and a bias toward large preswirl angles rather than counter-swirl during practical operation. The designs were carried out by computational fluid dynamics (CFD) and first tested in a steady, full-annulus cascade in order to quantify pressure losses and flow quality at the inlet to the impeller at different IGV setting angles (ranging from −20 deg to +60 deg) and flow rates. Subsequently, the designs were mounted in front of a typical oil and gas impeller on a high-speed rotating rig in order to determine the impact of flow distortion on the impeller performance. The results show that pressure losses in the inlet plenum could be reduced by up to 40% with the circumferentially nonuniform designs over the symmetric baseline configuration. Furthermore, a significant reduction in circumferential distortion could be achieved with the circumferentially nonuniform designs. The resulting improvement in impeller performance contributed approximately 40% to the overall efficiency gains for inlet plenum and impeller combined.

Introduction of Circumferentially Non-Uniform Variable Guide Vanes in the Inlet Plenum of a Centrifugal Compressor for Minimum Losses and Flow Distortion

2015 ◽  
Author(s):  
Ismail Sezal ◽  
Matthias Lang ◽  
Christian Aalburg ◽  
Nan Chen ◽  
Wolfgang Erhard ◽  
...  
Keyword(s):  
Variable Speed ◽  
Flow Distortion ◽  
Flow Rates ◽  
Guide Vanes ◽  
Baseline Design ◽  
Pressure Losses ◽  
Operating Range ◽  
Maximum Angle ◽  
Uniform Designs ◽  
The Impact

In the Oil & Gas industry, large variations in flow rates are often encountered which require compression trains with a wide operating range. If the stable operating range at constant speed is insufficient, variable speed drivers can be used to meet the requirements. Alternatively, variable guide vanes (IGVs) can be introduced into the inlet plenum to provide pre- or counter-swirl to the first stage impeller, possibly eliminating the need for variable speed. This paper presents the development and validation of circumferentially non-uniform IGVs that were specifically designed to provide maximum angle variation at minimum losses and flow distortion for the downstream impeller. This includes the comparison of three concepts: a baseline design based on circumferentially uniform and symmetric profiles and two circumferentially non-uniform concepts based on uniquely cambered airfoils at each circumferential position and a multi airfoil configuration consisting of a uniquely cambered fixed part and a movable part. The idea behind the circumferentially non-uniform designs was to take into account non-symmetric flow features inside the plenum and a bias towards large preswirl angles rather than counter-swirl during practical operation. The designs were carried out by CFD and first tested in a steady, full-annulus cascade in order to quantify pressure losses and flow quality at the inlet to the impeller at different IGV setting angles (ranging from −20° to +60°) and flow rates. Subsequently, the designs were mounted in front of a typical Oil & Gas impeller on a high speed rotating rig in order to determine the impact of flow distortion on the impeller performance. The results show that pressure losses in the inlet plenum could be reduced by up to 40% with the circumferentially non-uniform designs over the symmetric baseline configuration. Furthermore, a significant reduction in circumferential distortion could be achieved with the circumferentially non-uniform designs. The resulting improvement in impeller performance contributed approx. 40% to the overall efficiency gains for inlet plenum and impeller combined.

scholarly journals Impact of Orientation on the Thermal Performances in Vernacular Buildings in Hot Arid Climate

2019 ◽  
Vol 9 (2) ◽  
pp. 4840-4847
Keyword(s):  
Thermal Comfort ◽  
Large Scale ◽  
Cooling System ◽  
Vernacular Architecture ◽  
Climatic Conditions ◽  
Point Of View ◽  
Occupant Comfort ◽  
Vernacular Buildings ◽  
Scale Integration ◽  
The Impact

Morocco faces enormous climatic constraints. A large part of the national territory has a hot and dry climate, hence the importance of the climate aspect in the choice of an energy saving strategy. The use of reinterpreted, decontextualized, totally or partially vernacular architectural techniques and/or forms is visible at different levels in the Maghreb countries. The large-scale integration of this aspect seems to be ignored by the designers. The objective of this research is to evaluate the impact of the building orientation and vernacular architecture towards the occupant comfort, in order to meet its energy and comfort needs at a lower cost on one hand, and on the other hand, to design more efficient collective buildings from a thermal and energy point of view. The proposed methodology allows examining the thermal performances of a traditional building under the climatic conditions of the city of Rissani in order to naturally control comfort summer and winter, in addition to ensure a good thermal comfort without using any heating or cooling system. Finally, the simulations carried out lead to the identification of the optimal orientation that demonstrates an effective reduction in indoor temperatures and a decrease in the large daily fluctuations in these temperatures. The research focuses on the influence of the orientation of a building's facades in relation to the solar radiation and on providing the necessary thermal comfort.

scholarly journals Experimental studies on the hybrid system of heat and cold production from solar energy

2017 ◽  
Vol 21 (6 Part B) ◽  
pp. 2827-2835
Author(s):  
Stanislaw Gil ◽  
Boguslaw Gradon ◽  
Wojciech Bialik
Keyword(s):  
Solar Energy ◽  
Large Scale ◽  
Cooling System ◽  
Renewable Energy Sources ◽  
Experimental Studies ◽  
Hot Water ◽  
Temperate Climate ◽  
Water Tank ◽  
Energy Potential ◽  
The Impact

In recent years more and more energy is consumed in the European Union countries for summer air conditioning in buildings. This consumption will probably increase even more due to the predicted climate warming and the desire to improve the quality of life. At present final energy as heat and electricity is sourced mainly from fossil fuels. However, recently alternative renewable energy sources are increasingly taken into account as a result of efforts toward environmental protection and fuels savings. This paper presents results of the analysis of a hybrid solar-assisted heating and cooling system for buildings in the temperate climate of west and central Europe. Solar energy potential was estimated. The investigation was performed using a large scale laboratory installation, which contains an evacuated solar collector, a single-stage NH3-H2O absorption chiller and a hot water tank. The impact of the main system parameters on its performance was analyzed on the basis of energy balances.

scholarly journals Implementing Neuromarketing in the Enterprise: Factors That Impact the Adoption of Neuromarketing in Major Spanish Corporations

2020 ◽  
Vol 5 ◽  
Author(s):  
Verónica Crespo-Pereira ◽  
Beatriz Legerén-Lago ◽  
Jaime Arregui-McGullion
Keyword(s):  
Pilot Study ◽  
Large Scale ◽  
Full Scale ◽  
External Factors ◽  
General Level ◽  
Online Questionnaire ◽  
Distribution Method ◽  
Main Factors ◽  
Internal And External Factors ◽  
The Impact

Technological advances in the field of neuroscience have generally been well-received in the entertainment and advertising industries, where there are great commercial benefits linked to knowing the most intimate aspects of how audiences and consumers respond to different messages. Despite this interest in the results of neuroscience research, large enterprises seem to resist implementing them in their marketing activities, thus limiting the development of the discipline. This research reflects on the main factors that impact the adoption of neuromarketing within large-scale enterprises, both from a bibliographical and an empirical perspective. This review included ethical, economic, professional, technological, and cultural aspects. A review of secondary sources was undertaken to understand the current state of neuromarketing and its place within large-scale enterprises. This review suggested that a series of internal and external factors may be limiting its adoption, including organizational culture, lack of knowledge and training, uncertainty about its results and/or concerns about the cost of this methodology. To validate the results of the bibliographical research, a structured, self-administered online questionnaire was designed to be distributed amongst a senior decision makers within large companies in Spain. The aims of this survey were to diagnose the level to which major corporations in Spain are aware of and employ neuromarketing; and to identify the internal and external factors that may be limiting or driving its rate of adoption. Before running a full-scale study, a pilot test was undertaken to, among others, validate the sampling methods and survey distribution strategy and to measure the impact of some major challenges that had been identified during survey design. The pilot study did succeed in reaching highly qualified respondents, but its low response rate highlighted a major issue in the research design: the sampling method cannot scale efficiently. A full review of the sampling strategy and survey distribution method is needed before a full-scale study can be launched. The data gathered in the pilot study can't be considered representative or statistically valid; they are, at best, preliminary findings that will need to be validated by further research. The responses do suggest that neuromarketing techniques are not used in the majority of large Spanish companies and that the general level of knowledge on the subject is not very high. The results also suggest that neuromarketing has a good reputation amongst industry practitioners and that, if current trends are confirmed, its adoption will increase significantly in the future. The main factors that would drive the adoption of neuromarketing are the culture of innovation of the companies themselves and the direct alignment of neuromarketing techniques to the market research needs on the company. Further research in this area should take into account the learnings provided by this pilot.

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