Innovative Ram Air Turbine for Airborne Power Generation

Author(s):  
Daniel Haid ◽  
John Justak

An innovative high power density and low drag ram air turbine for airborne power generation has been developed. Future systems on military and commercial aircraft will require greater electrical power. Unfortunately, expanding the capacity of the electrical systems on current aircraft and ones in development can result in costly design changes, require recertification, and significantly impact performance. Powering these systems locally with batteries is often considered. However, operation time is limited by the battery and the additional weight can limit aircraft range. The innovative ram air turbine design configuration described here has a power density that can be significantly higher than batteries and a lower drag and greater integration flexibility than conventional ram air turbines. Unlike batteries, which have a finite specific energy, the ram air turbine is only limited by the flight time of the vehicle. This system has a ducted turbine located in a pod or fuselage interior, unlike current ram air turbines that are externally mounted and require direct exposure to the free-stream flow. The internally mounted ram air turbine contributes less to overall aerodynamic drag than current ram air turbines, allows for more power to be extracted in an equivalent design space, and offers reduced radar signature compared to present externally-bladed turbines. Computational analyses along with wind tunnel testing have been conducted in support of this design. A 25-inch (0.635 m) diameter turbine demonstrated 110 kW of electrical power over a wide range of Mach numbers and simulated altitudes.

Author(s):  
Henry Z. Graham ◽  
Meagan Hubbell ◽  
Chad Panther ◽  
Jay Wilhelm ◽  
Gerald M. Angle ◽  
...  

Wind turbines are a source of renewable energy with an endless supply. The most efficient types of wind turbines operate by utilizing the lift force of its blades to create a rotational force. The power capabilities of a wind turbine are tied to the blades’ ability to convert the aerodynamic forces into rotational energy. Vertical axis wind turbines (VAWT), unlike the more common horizontal axis (HAWT) type, do not need to be directed into the wind and can place the transmission and electrical power generation components at the bottom of the turbine shaft, near the ground. Currently VAWTs cannot feather or pitch the blades, in the same fashion as a HAWT, for a lift change to control power generation and/or rotational speed at different or changing wind speeds. A method of increasing the lift of a blade without physically moving the blade is to use circulation control (CC), via a blowing slot over a rounded trailing edge. The CC air flow entrains the air around the blade to create more lift. Adding an actuated valve for the blowing slot allows a CC-VAWT to control the amount of lift generated, as well as the location of the augmentation relative to the wind direction, resulting in augmented power generation. In order to study the performance capabilities of a CC-VAWT, a NACA0018 blade was modified to incorporate circulation control. This modified shape was analyzed using computational fluid dynamics at two Reynolds numbers and a wide range of angles of attack. The lift to drag ratio of the CC-VAWT blade shows benefits at low Reynolds numbers over a NACA0018 blade for post stall angles of attack, but there is a decrease in the lift to drag before stall due to a significant increase in drag of the circulation control models. Further CFD refinement and experimental investigations are recommended to validate the predicted effects circulation control will have on the performance of a VAWT.


Author(s):  
Kevin Smith ◽  
Emil Sandoz-Rosado ◽  
Crisson Jno-Charles ◽  
Clement Henry ◽  
Erik Herrmann ◽  
...  

The characterization of thermoelectric modules for power generation applications has only received minimal attention by researchers. This paper describes the development of a test stand for the characterization of the thermoelectric power modules. The test stand has the ability to provide constant temperatures on the hot and cold side of thermoelectric modules and measure the amount of electrical power generated. Great care was taken to provide a uniform temperature on both the hot side and cold side of the module, with the hot side having the capability to provide temperatures of up to 600°C and the cold side able to be maintained at room temperature. The system is able to deliver a controlled heat flux of 140 kW/m2 to a thermoelectric module. A data acquisition system was developed to record the electrical performance of tested modules under a wide range of operating temperatures regulated by the control system. Using the collected data it will be possible to compare many modules and evaluate their performance with one another as well as provide module power generation parameters which can be useful for thermoelectric system design. This project was commissioned through the RIT Multidisciplinary Senior Design program as a capstone to the undergraduate degree curricula.


Author(s):  
Harikrishnan R ◽  
K.C James

Usually Electrical Power is generated in large scale using Air Compressors and Gas Turbine Systems. This type of Power plants is usually used as Peak load Power Plants. These Power Plants can assist in various power generation process along with base load power plants like Thermal Power Plants, Combined cycle power plants etc. Here in this Research paper, a new method of Power generation is being discussed. It utilizes an Air Compressor-Air Turbine System for Electrical Power generation by means of effective power transmission. This method is simple and less costly. It requires less space and less skilled laborer. It can be used in Stand by and Emergency power generation systems. An ANN model is carried out which gives satisfactory working conditions. The cost analysis is being carried out by considering small capacity and micro power production conditions. The efficiency attained during this method of power generation is around 55%. By incorporating large macro energy systems, we can produce more power output and also generate more electrical power. By considering all these factors it can be considered as a very good working model.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rohith Mittapally ◽  
Byungjun Lee ◽  
Linxiao Zhu ◽  
Amin Reihani ◽  
Ju Won Lim ◽  
...  

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Joffrey L. Leevy ◽  
John Hancock ◽  
Richard Zuech ◽  
Taghi M. Khoshgoftaar

AbstractMachine learning algorithms efficiently trained on intrusion detection datasets can detect network traffic capable of jeopardizing an information system. In this study, we use the CSE-CIC-IDS2018 dataset to investigate ensemble feature selection on the performance of seven classifiers. CSE-CIC-IDS2018 is big data (about 16,000,000 instances), publicly available, modern, and covers a wide range of realistic attack types. Our contribution is centered around answers to three research questions. The first question is, “Does feature selection impact performance of classifiers in terms of Area Under the Receiver Operating Characteristic Curve (AUC) and F1-score?” The second question is, “Does including the Destination_Port categorical feature significantly impact performance of LightGBM and Catboost in terms of AUC and F1-score?” The third question is, “Does the choice of classifier: Decision Tree (DT), Random Forest (RF), Naive Bayes (NB), Logistic Regression (LR), Catboost, LightGBM, or XGBoost, significantly impact performance in terms of AUC and F1-score?” These research questions are all answered in the affirmative and provide valuable, practical information for the development of an efficient intrusion detection model. To the best of our knowledge, we are the first to use an ensemble feature selection technique with the CSE-CIC-IDS2018 dataset.


2001 ◽  
Vol 28 (1) ◽  
pp. 98-110 ◽  
Author(s):  
Bruce F Sparling ◽  
Alan G Davenport

Large amplitude cable vibrations are difficult to predict using linear theory due to the presence of sag in the suspended profile. A numerical study was therefore undertaken to investigate the dynamic behaviour of inclined cables excited by imposed displacements. To model the nonlinear nature of cable response, a time domain finite element approach was adopted using nonlinear catenary cable elements. Two types of horizontal displacement patterns were enforced at the upper end of the guy. In the first phase of the study, harmonic displacement histories with a wide range of forcing frequencies were considered. In the second phase, random enforced displacements were used to simulate the motion of a guyed mast in gusty winds. The influence of aerodynamic drag and damping forces was investigated by performing analyses under still air, steady wind, and turbulent wind conditions. It was found that nonlinear coupling of related harmonic response components was significant at certain critical frequencies, particular when the excitation was harmonic and acted in the plane of the guy. Positive aerodynamic damping was shown to effectively suppress resonant and nonlinear coupling response.Key words: cables, structural dynamics, wind loading, finite element method, nonlinear analysis, guyed towers.


Author(s):  
K. R. Wilt ◽  
H. A. Scarton ◽  
G. J. Saulnier ◽  
T. J. Lawry ◽  
J. D. Ashdown

Throughout the last few years there has been a significant push to develop a means for the transmission of electrical power through solid metallic walls using ultrasonic means. The bulk of this effort has been focused on using two coaxially aligned piezoelectric transducers on opposite sides of a thick metallic transmission barrier, where one transducer serves as the “transmit” transducer and the other as the “receive” transducer. Previous modeling has predicted reasonably high power transfer efficiencies through the wall using this type of “acoustic-electric channel” to be possible at low power levels, which implies that channel component operates in a linear range with little concern of failure. High-power testing of two acoustic-electric channels has been done in an effort to determine power limits on such channels and to determine levels at which non-linear effects on the piezoelectrics become non-negligible. The tested channels are characterized by the “power density” imposed on the transmit transducer, that is, the power applied per unit area, as the values found for maximum power density are considered to be independent of transducer radii. The constructed channels are shown to be capable of transmitting large amounts of power (over 100 watts) without failure; and further, extrapolation of the results to channels with larger diameter transducers predicts power transfer of 1 kW to be highly feasible.


2015 ◽  
Vol 193 (3) ◽  
pp. 17-23 ◽  
Author(s):  
Fumihiko Komatsu ◽  
Manabu Tanaka ◽  
Tomoyuki Murakami ◽  
Yoshihiro Okuno

1977 ◽  
Vol 33 (2) ◽  
pp. 212-222 ◽  
Author(s):  
R. W. Hardie ◽  
J. H. Chamberlin

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