Aerodynamic force data for a V-style ski jumping flight

2004 ◽  
Vol 7 (1) ◽  
pp. 31-39 ◽  
Author(s):  
K. Seo ◽  
I. Watanabe ◽  
M. Murakami
Keyword(s):  
Aerodynamic Force ◽  
Ski Jumping ◽  
Force Data

Desirable Gliding Styles and Techniques in Ski Jumping

1995 ◽  
Vol 11 (4) ◽  
pp. 460-474 ◽  
Author(s):  
Hiroshi Jin ◽  
Shunsuke Shimizu ◽  
Tadaharu Watanuki ◽  
Hirotoshi Kubota ◽  
Kazutoshi Kobayashi
Keyword(s):  
Angular Velocity ◽  
Sagittal Plane ◽  
Aerodynamic Force ◽  
Frontal Plane ◽  
Flight Phase ◽  
Ski Jumping ◽  
Force Data ◽  
Positive Factor ◽  
Late Part

Desirable flight styles and techniques in ski jumping were calculated on the basis of the new aerodynamic force data for three styles: classic style, V style, and flat V style. In the V style and flat V style two skis are in a herringbone position in the frontal plane, whereas in the classic style the skis are parallel Flat V style is more flat in the sagittal plane than V Style. The most effective style was the flat V style if a ski jumper model did not change style during the gliding phase, which was the late part of flight phase (distance was 110 m). If the model changed flight style, the model that changed from classic style to V style at 1.3 s after takeoff or from flat V style to V style at 1.6 s could achieve 112.5 m. In addition, forward initial angular velocity was a positive factor to increase distance; in particular, the distance for the V style was sensitive to initial angular velocity.

scholarly journals Multi-Fidelity Surrogate Models for VPP Aerodynamic Input Data

2021 ◽  
Vol 6 (01) ◽  
pp. 21-43
Author(s):  
Tanya Peart ◽  
Nicolas Aubin ◽  
Stefano Nava ◽  
John Cater ◽  
Stuart Norris
Keyword(s):  
Aerodynamic Force ◽  
Computational Cost ◽  
Computational Effort ◽  
Force Coefficient ◽  
Cfd Models ◽  
Research Activities ◽  
Velocity Prediction ◽  
Computational Fluid Dynamics Cfd ◽  
Lift And Drag ◽  
Force Data

Predicting the performance of a sail design is important for optimising the performance of a yacht, and Velocity Prediction Programs (VPPs) are commonly used for this purpose. The aerodynamic force data for a VPP is often calculated using Computational Fluid Dynamics (CFD) models, but these can be computationally expensive. A full VPP analysis for sail design is therefore usually restricted to high-budget design projects or research activities and is not practical for many industry projects. This work presents a method to reduce the computational cost of creating lift and drag force coefficient curves for input into a VPP using both multi-fidelity kriging surrogate modelling and data from existing sail designs. This method is shown to reduce the number of CFD simulations required for a desired accuracy when compared to a single-fidelity model. A maximum reduction in the required computational effort of 57% was achieved for model-scale symmetric spinnaker sails. For the same number of simulations, the accuracy of the model predictions was improved by up to 72% for scale-symmetric spinnaker sails, and 90% for asymmetric spinnakers.

An Analysis Method of Static Aeroelastic Response with Nonlinear Aerodynamic Data on 3D Bodysurface Panel Element

2013 ◽  
Vol 444-445 ◽  
pp. 764-770
Author(s):  
Yao Kun Wang ◽  
Zhi Qiang Wan ◽  
Shan Liu
Keyword(s):  
Aerodynamic Force ◽  
Aircraft Design ◽  
Navier Stokes ◽  
Analysis Method ◽  
Aeroelastic Response ◽  
Response Characteristics ◽  
Aerodynamic Pressure ◽  
Euler Solver ◽  
Force Data ◽  
Nonlinear Aerodynamic

A static aeroelastic responses analysis method based on mapping external nonlinear aerodynamic forces onto 3D body surface panel elements is proposed. The external nonlinear aerodynamic force data can be obtained by Euler solver, Navier-Stokes solver and wind tunnel tests. In this paper, the method is applied to obtain static aeroelastic responses of a flexible aircraft, and the emphasis is placed on the change of aerodynamic coefficient, aerodynamic pressure distribution and flight load. The results are compared with static aeroelastic responses calculated by high-order panel method. It is concluded that the method presented in this study is feasible, credible and efficient, and can provide an assessment of static aeroelastic response characteristics for the detailed stage of aircraft design.

Comparative Responses to Squats Completed with Free Weights and an Exoskeleton

2020 ◽  
Vol 4 (1) ◽  
pp. 51-63
Author(s):  
Peter Neuhaus ◽  
Chris Jumonville ◽  
Rachel A. Perry ◽  
Roman Edwards ◽  
Jake L. Martin ◽  
...  
Keyword(s):  
Data Collection ◽  
Female Athletes ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Actual Data ◽  
Limited Data ◽  
Comparative Similarity ◽  
Insufficient Amount ◽  
Force Data ◽  
Familiarization Session

AbstractTo assess the comparative similarity of squat data collected as they wore a robotic exoskeleton, female athletes (n=14) did two exercise bouts spaced 14 days apart. Data from their exoskeleton workout was compared to a session they did with free weights. Each squat workout entailed a four-set, four-repetition paradigm with 60-second rest periods. Sets for each workout involved progressively heavier (22.5, 34, 45.5, 57 kg) loads. The same physiological, perceptual, and exercise performance dependent variables were measured and collected from both workouts. Per dependent variable, Pearson correlation coefficients, t-tests, and Cohen's d effect size compared the degree of similarity between values obtained from the exoskeleton and free weight workouts. Results show peak O2, heart rate, and peak force data produced the least variability. In contrast, far more inter-workout variability was noted for peak velocity, peak power, and electromyography (EMG) values. Overall, an insufficient amount of comparative similarity exists for data collected from both workouts. Due to the limited data similarity, the exoskeleton does not exhibit an acceptable degree of validity. Likely the cause for the limited similarity was due to the brief amount of familiarization subjects had to the exoskeleton prior to actual data collection. A familiarization session that accustomed subjects to squats done with the exoskeleton prior to actual data collection may have considerably improved the validity of data obtained from that device.

Withdrawal: Ascent Aerodynamic Force and Moment Database Development for the Space Launch System

2019 ◽  
Author(s):  
Patrick R. Shea ◽  
Jeremy T. Pinier ◽  
Heather P. Houlden ◽  
Amber L. Favaregh ◽  
Michael J. Hemsch ◽  
...  
Keyword(s):  
Aerodynamic Force ◽  
Database Development ◽  
Space Launch

Extremely Gusty Winds from a Viewpoint of Aerodynamic Force

2020 ◽  
Author(s):  
Junji Maeda ◽  
Takashi Takeuchi ◽  
Eriko Tomokiyo ◽  
Yukio Tamura
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Rise Time ◽  
Aerodynamic Force ◽  
Step Function ◽  
Object Size ◽  
Aerodynamic Forces ◽  
Wind Force ◽  
Wind Observation

To quantitatively investigate a gusty wind from the viewpoint of aerodynamic forces, a wind tunnel that can control the rise time of a step-function-like gust was devised and utilized. When the non-dimensional rise time, which is calculated using the rise time of the gusty wind, the wind speed, and the size of an object, is less than a certain value, the wind force is greater than under the corresponding steady wind. Therefore, this wind force is called the “overshoot wind force” for objects the size of orbital vehicles in an actual wind observation. The finding of the overshoot wind force requires a condition of the wind speed recording specification and depends on the object size and the gusty wind speed.

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