Rotor Design for High-Speed Flywheel Energy Storage Systems
Bibliographic record
Abstract
1.1 Kinetic energy storage using flywheels Devices employing the concept of kinetic energy storage date back to ancient times. Pottery wheels and spinning wheels are early examples of systems employing kinetic energy storage in a rotating mass. With the advent of modern machinery, flywheels became commonplace as steam engines and internal combustion engines require smoothing of the fluctuating torque that is produced by the reciprocating motion of the pistons of such machines. More recently, flywheel systems were developed as true energy storage devices, which are also known as mechanical or electromechanical batteries. A remarkable example of such a system was the sole power source of the ’Gyrobus’ a city bus that was developed by the Maschinenfabrik Oerlikon in Switzerland in the 1930’s, see Motor Trend (1952). This vehicle contained a rotating flywheel that was connected to an electrical machine. At regular bus stops, power from electrified charging stations was used to accelerate the flywheel, thus converting electrical energy to mechanical energy stored in the flywheel. When traveling between bus stops, the electrical machine gradually decelerated the flywheel and thus converted mechanical energy back to electricity, which was used to power the electrical motor driving the bus. The disk-shaped flywheel rotor was made of steel, had a mass of about 1.5 metric tons and reached a maximum angular velocity of 314 rad/s or 3000 rounds per minute (rpm). In regular operation, deceleration of the flywheel was limited to about half of the maximum disk speed. The amount of energy thus made available allowed the Girobus to travel for a distance of up to 6 km in regular traffic. Contemporary flywheel energy storage systems, or FES systems, are frequently found in high-technology applications. Such systems rely on advanced high-strength materials as flywheels usually operate at speeds exceeding 10,000 rpm. Vacuum enclosures and magnetic bearing systems are frequently employed to minimize energy losses due to friction. Only through the use of advanced technology have FES systems become commercially viable for a range of applications, causing FES research and development to be an active and rapidly evolving field. 3
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.010 | 0.004 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".