Browse Topic: Electric power
The present work focuses on the sizing and analysis of a parallel hybrid propulsion architecture for a conventional rotary light Unmanned Aerial Vehicle (UAV) in the 200kg class. First, the design methodology is outlined, with an emphasis on the optimization of the battery pack, which is one of the most crucial component of the whole powertrain. The sizing approach is applied to a wide range of thermal and electric power ratios, as well as two distinct hybridization strategies, to investigate the broad design space and discover possible sweet spots. For this aim, the various design points are then evaluated in terms of impact on aircraft capabilities, considering both extensive and intensive performance. Hence, the results provide the main advantages and disadvantages, performance wise, of the hybrid propulsion in comparison to a conventional full thermal solution.
Propeller driven rotors utilize propellers on the main rotor blade to spin the rotor. Past research efforts have highlighted dynamic issues that arise from the rotor-propeller Coriolis interaction. For this paper, a comprehensive multi-body analysis methodology, called Elastic Rotorcraft Analysis (ERA), was applied to various propeller driven rotor datasets. The focus of the modeling effort was on propeller driven rotor twirl phenomenon, which arises from rotor-propeller inertial couplings interacting with rotor blade modes. After describing the phenomenon, the paper is split into two parts: validations and predictions. In Part I of the paper, the ERA propeller driven rotor model was validated using three datasets: (i) a propeller flapping vacuum chamber experiment, (ii) a propeller/rotor loads vacuum chamber experiment, and (iii) a propeller driven rotor hover experiment. The ERA model showed good agreement with the data, and captured the important rotor-propeller Coriolis interaction. In Part II of the paper, predictions for several propeller driven rotor configurations were generated and analyzed. Loads were computed for an isolated propeller and are compared to propeller loads during propeller driven rotor operation. The analysis showed that operating the propeller on the rotor blade introduces significant inertial loads on the propeller. Finally, propeller placement along the main rotor blade span was investigated. The results of the present study agree with earlier research, which showed placing the propeller at the midspan location reduced the electrical power coefficient by nearly half compared to a tip mounted propeller.
Toyota's big claim for its new sixth-generation 2026 RAV4 is that the SUV is now“ 100% electrified.” That's true, as Obi-wan once said, from a certain point of view. As it recently did with the Camry, the automaker has eliminated an ICE-only powertrain from the list of options, giving drivers the choice between a gas-electric hybrid or a plug-in hybrid (PHEV). The hybrids use Toyota's fifth-generation hybrid system, which uses a 2.5-L 4-cylinder aluminum Atkinson cycle engine that produces 163 lb-ft and up to 226 hp (169 kW) in FWD configuration, 236 hp (176 kW) in AWD. Seven trim levels - LE, XLE Premium (which Toyota expects to be the volume trim), Limited, SE, XSE and Woodland - can be had with the hybrid powertrain, while the driving-focused GR Sport version can only be had as a PHEV. The plug-in option is available on the SE, XSE and Woodland. These new RAV4s use Toyota's sixth-generation PHEV system, which produces 324 hp (242 kW) and up to 172 lb-ft So, yes, the entire line-up is electric, but most are also gas-powered.
Leonardo DRS Arlington, VA mmount@drs.com
The growing demand for improved fuel efficiency and reduced emissions in diesel engines has led to significant advancements in power management technologies. This paper presents a dual-mode functional strategy that integrates electrified turbochargers to enhance engine performance, provide boost and generate electrical power. This helps in optimizing the overall engine efficiency. The engine performance is enhanced with boosting mode where the electric motor accelerates the turbocharger independent of exhaust flow, effectively reducing turbo lag and provides immediate boost at low engine speeds. This feature also improves high altitude performance of the engine. Conversely, in generating mode, the electric turbocharger recovers or harvest energy from exhaust gases depending on engine operating conditions, converting it into electrical energy for battery recharging purpose. Advanced control systems enable real-time adjustments to boost pressure and airflow in response to dynamic driving conditions, maximizing engine efficiency. Simulation studies and engine testing validate the expected benefits, demonstrating that the electrified turbocharger can significantly facilitate engine downsizing, reduce fuel consumption, and lower emissions through precise power management. These advancements align with global sustainability goals, presenting a viable solution to meet stringent environmental regulations while maintaining robust engine performance. The integration of electrified turbochargers represents a critical step towards the next generation of eco-friendly diesel engines, supporting both environmental sustainability and economic efficiency.
A new bioimaging device can operate with significantly lower power and in an entirely non-mechanical way. It could one day improve detecting eye and even heart conditions. The device uses a process called electrowetting to change the surface shape of a liquid to perform optical functions. By creating a device that doesn’t use scanning mirrors, the technique requires less electrical power than other devices used for OCT and bioimaging. To test the device’s ability to perform biomedical imaging, the researchers turned to zebrafish. The researchers focused on identifying where the cornea, iris, and retina was from the zebrafish. The two benchmarks that the group hoped to achieve were 10 μm in axial resolution and then around 5 μm in lateral resolution.
While electric powertrains are driving 48V adoption, OEMs are realizing that xEV and ICE vehicles can benefit from a shift away from 12-volt architectures. In every corner of the automotive power engineering world, there are discussions and debates over the merits of 48V power networks vs. legacy 12V power networks. The dialogue started over 20 years ago, but now the tone is more serious. It's not a case of everything old is new again, but the result of a growing appetite for more electrical power in vehicles. Today's vehicles - and the coming generations - require more power for their ADAS and other safety systems, infotainment systems and overall passenger comfort systems. To satisfy the growing demand for low-voltage power, it is necessary to boost the capacity of the low-voltage power network by two or three times that of the late 20th century. Delivering power is more efficient at a higher voltage, and today, 48V is the consensus voltage for that higher level.
Researchers at the National Aeronautics and Space Administration (NASA) have conducted a series of module-level tests on electric Vertical Take-off and Landing (eVTOL) Energy Storage Systems (ESS) for the generation of dynamic impact data to support standards developments. The tests were conducted on zero-state-of-charge Electric Power Systems (EPS) Electric Propulsion Ion Core (EPIC) modules at the National Institute for Aviation Research (NIAR), utilizing the NIAR outdoor drop test setup and personnel. Four total tests were conducted. For each test, the module was dropped at a specific orientation from a height of 50 feet while connected to a guided trolley in order to assess the effects of a 50-foot drop test on the ESS. The test velocities ranged between 46.9 and 52.8 ft/s with impact angles ranging between a flat, zero-degree impact and 18 degrees. Data were recorded in the form of temperatures, cell-level voltage, module level acceleration and digital image correlation from the tests. Accelerations were in the range of 1,500 g for a few millisecond duration, which were indicative of a shock type loading condition. No modules entered thermal runaway, and post-test inspections revealed a variety of internal deformations and damage present in the various modules tested, with specific damage occurring for specific orientations. The modules were ranked according to a custom developed scoring rubric developed by utilizing the test and post-test inspection results. The results were compiled, reported, and will be used to guide future ESS testing. Part 1 discusses the loading environments in the modules, while Part 2 will discuss the deformation and damage in the modules.
Researchers at the National Aeronautics and Space Administration (NASA) have conducted a series of module-level 50-ft dynamic drop tests on electric Vertical Take-off and Landing (eVTOL) Energy Storage Systems (ESS) for the generation of dynamic impact data to support standards developments. The tests were conducted on zero-state-of-charge Electric Power Systems (EPS) Electric Propulsion Ion Core (EPIC) modules at the National Institute for Aviation Research (NIAR), utilizing the NIAR outdoor drop test setup and conducted by NIAR test personnel. Four total tests were conducted on modules oriented in four different orientations. During initial post-test inspections at the drop facility, it was observed that the modules experienced varying amounts of damage in various locations and forms. The damage was quantified to the maximum extent possible via photogrammetric methods such as digital image correlation and marker tracking. Post-test modules were then disassembled, and forensics were conducted, which involved inspections into various containment structures and the cells themselves. A scoring rubric was developed in order to utilize a common methodology to quantitatively assess the damage incurred into each module as way of determining the least and most amount of damage present. Results in the form of post-test inspections, digital image correlation deformations, and scoring rubric values will be all presented, along with proposed paths forward for future work.
Aircraft Certification is a mature and complex bureaucracy that has successfully ensured a very high degree of safety of aircraft design, construction, operation and maintenance. Outside of a very few doing the work, there is a general lack of knowledge of certification details. For novel technologies such as electric power, and innovative configurations such as multi-rotors, the rules are far less mature and still emerging and so also poorly understood. Within the Advanced Air Mobility (AAM) initiative, many new aircraft developments are underway using novel configurations, and the public announcements of regulatory progress toward FAA or EASA Type Certification capitalize on this ignorance by being vague or even misleading. Honeywell conceived the Regulatory Readiness Level (RRL) indicator as an objective measure of certification status to serve the AAM industry and ecosystem, with applicability across aviation. The released RRL Version 1 now enables credible, objective assessment of new aircraft progress toward FAA Type Certification, and Operational Approval for Part 135 operations, to allow consistent apples-to-apples comparisons with other aircraft in development. An emerging complementary version of the rubric for EASA Type Certification is ready for publication to enable RRL determination against the European Union criteria. Future releases will consider other Nation's regulatory authorities, supplemental types certifications (STCs), and risk-based airworthiness assessments such as the Specific Operations Risk Assessments (SORA).
In addition to providing safety advantages, sound and vibration are being utilized to enhance the driver experience in Battery Electric Vehicles (BEVs). There's growing interest and investment in using both interior and exterior sounds for pedestrian safety, driver awareness, and unique brand recognition. Several automakers are also using audio to simulate virtual gear shifting of automatic and manual transmissions in BEVs. According to several automotive industry articles and market research, the audio enhancements alone, without the vibration that drivers are accustomed to when operating combustion engine vehicles, are not sufficient to meet the engagement, excitement, and emotion that driving enthusiasts expect. In this paper, we introduce the use of new automotive, high-force, compact, light-weight circular force generators for providing the vibration element that is lacking in BEVs. The technology was developed originally for vibration reduction/control in aerospace applications, has been recently tested in various vehicles, and demonstrates the effectiveness for providing a real haptic feel across the entire vehicle. Shaking the vehicle globally provides a unique capability for BEVs, including Hybrid Electric Vehicles and for helping to create a smooth transition between Gas and Electric power, for example. The technology can be used to generate and emulate high-performance, high power, combustion engine feel, including idle, engine run-up/acceleration, simulated gear shifts, and Advanced Driving Assistance and Systems (ADAS) haptic indicators. The optional and customizable vibration can also mask road vibration which becomes very noticeable in otherwise smooth BEVs and can provide the perfect supplement to existing audio enhancements and gear shifting features. Additionally, the paper describes how the force generating device can be packaged in a light weight, compact, low-power manner. The technology will be compared to other force generating methods, and discuss its pros and cons.
In this study, vibration characteristics inside an electric power unit at gravity center where direct measurement is impossible were estimated by using virtual point transformation to consider guideline for effective countermeasures to the structure or generated force characteristics inside the power source. Vibration acceleration, transfer function and the generated force in operation at the gravity center of the electrical power source were obtained by vibration characteristics at around the power source which can be measured directly. In addition, the transfer functions from the gravity center to the power source attachment points on the product were also estimated. And then, the contribution from the gravity center to the power unit attachment point was obtained by multiplying generated force with the transfer function. As results, the obtained total contribution was almost same with the actual measured vibration at the attachment point. Furthermore, the rotational contribution from the gravity center was found to be larger than translational contribution at the attachment point vibration along front-back direction.
Electrochemical machining (ECM) is a highly efficient method for creating intricate structures in materials that conduct electricity, irrespective of their hardness. Due to the increasing demand for superior products and the necessity for quick design modifications, decision-making in the manufacturing sector has become progressively more difficult. This study focuses on Cupronickel and suggests creating predictive models to anticipate performance metrics in ECM through regression analysis. The experiments are formulated based on Taguchi's principles, and a multiple regression model is utilized to deduce the mathematical equations. The Taguchi approach is employed for single-objective optimization to ascertain the ideal combination of process parameters for optimizing the material removal rate. The proposed prediction technique for Cupronickel is more adaptable, efficient, and accurate in comparison to current models, providing enhanced monitoring capabilities. The updated models have been verified, demonstrating a robust link between empirical data and projected results.
Electrochemical machining (ECM) is a highly efficient method for creating intricate structures in materials that conduct electricity, independent of their level of hardness. Due to the increasing demand for superior products and the necessity for quick design modifications, decision-making in the manufacturing sector has become progressively more difficult. This study primarily examines the use of Haste alloy in vehicle applications and suggests creating regression models to predict performance parameters in ECM. The experiments are formulated based on Taguchi's ideas, and mathematical equations are derived using multiple regression models. The Taguchi approach is employed for single-objective optimization to ascertain the ideal combination of process parameters for optimizing the material removal rate. ANOVA is employed to evaluate the statistical significance of process parameters that impact performance indicators. The proposed regression models for Haste alloy are more versatile, efficient, and accurate in comparison to the current models, providing enhanced monitoring capabilities. The updated models have been verified, demonstrating a robust link between empirical data and projected results.
Aircraft Certification is a mature and complex bureaucracy that has successfully ensured a very high degree of safety of aircraft design, construction, operation and maintenance. Outside of a very few professionals doing the work, there is a general lack of knowledge of certification details. For novel technologies such as electric power, and for innovative configurations such as distributed lift and lift-plus-lift-cruise, the rules are far less mature and still emerging and so also poorly understood. Within the Advanced Air Mobility (AAM) initiative, many new aircraft developments are underway using novel configurations, and the public announcements of regulatory progress toward FAA or EASA Type Certification capitalize on this unfamiliarity by being vague or even misleading. Honeywell conceived the Regulatory Readiness Level (RRL) indicator as an objective measure of certification status to serve the AAM industry and ecosystem, with applicability across all of aviation. RRL Version 1 enables a credible, objective assessment of new aircraft progress toward FAA Type Certification, and Operational Approval for Part 135 operations, to allow consistent apples-to-apples comparisons with other aircraft in development. Future RRL releases with allow determination of progress against criteria from EASA and other regulatory authorities, for supplemental types certifications STCs), and for risk-based airworthiness assessments such as EASA Specific Operations Risk Assessments (SORA).
A novel method of swashplateless rotor control is presented for a propeller driven rotor. A propeller driven rotor consists of small electric motors and propellers attached to the rotor blade to spin the main rotor. The control methodology involves varying the propeller RPM around one rotor revolution to generate rolling and pitching moments for the main rotor. A small test stand was fabricated using 2.7 ft diameter 3D printed rotor blades to investigate this concept with various tip propeller geometries. The test stand was utilized to characterize changes in motor commands to rotor rolling and pitching moments. Next, in an effort to reduce the required power for the propeller driven rotor, the propeller placement along the rotor blade span was varied. Placing the propeller at the mid span location on the main rotor blade resulted in a significant reduction of 50% in the electrical power loading coefficient CPe/σ compared to a tip propeller placement. Finally, the propeller driven rotor control strategy was experimentally compared with a 6 ft diameter, shaft driven rotor that used a conventional swashplate system. A comparison of the control authority derivatives for the different configurations showed that the propeller driven rotor control strategy resulted in a similar amount of control authority as a conventional swashplate system.
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