Effects of moment of inertia on restricted motion swing speed

The purpose of this study was to examine the batting cage performance of wood and nonwood baseball bats used at the youth level. Three wood and ten nonwood bats were swung by 22 male players (13 to 18 years old) in a batting cage equipped with a 3-dimensional motion capture (300 Hz) system. Batted ball speeds were compared using a one-way ANOVA and bat swing speeds were analyzed as a function of bat moment of inertia by linear regression. Batted ball speeds were significantly faster for three nonwood bat models (P< .001), significantly slower for one nonwood model, and not different for six nonwood bats when compared with wood bats. Bat impact speed significantly (P< .05) decreased with increasing bat moment of inertia for the 13-, 14-, and 15-year-old groups, but not for the other age groups. Ball-bat coefficients of restitution (BBCOR) for all nonwood were greater than for wood, but this factor alone did not correlate with bat performance. Our findings indicate that increases in BBCOR and swing speed were not associated with faster batted ball speeds for the bats studied whose moment of inertia was substantially less than that of a wood bat of similar length.

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Effect of Moment of Inertia and Physical Profile on Restricted Motion Swing Speed

Procedia Engineering ◽

10.1016/j.proeng.2014.06.086 ◽

2014 ◽

Vol 72 ◽

pp. 593-598 ◽

Cited By ~ 1

Author(s):

Dave Schorah ◽

Simon Choppin ◽

David James

Keyword(s):

Moment Of Inertia ◽

Physical Profile ◽

Swing Speed

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Perception of the moment of inertia of hand tools

PsycEXTRA Dataset ◽

10.1037/e573972012-006 ◽

1982 ◽

Author(s):

Carol Zahner ◽

M. Stephen Kaminaka

Keyword(s):

Moment Of Inertia ◽

Hand Tools ◽

The Moment

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The moment of inertia of common objects: a prediction equation and its relevance to design

PsycEXTRA Dataset ◽

10.1037/e574062012-011 ◽

1983 ◽

Author(s):

J. G. Kreifeldt ◽

R. Morse

Keyword(s):

Prediction Equation ◽

Moment Of Inertia ◽

The Moment

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A novel semi-active actuator with tunable mass moment of inertia for noise control applications

Journal of Sound and Vibration ◽

10.1016/j.jsv.2021.116244 ◽

2021 ◽

pp. 116244

Author(s):

Stanislaw Wrona ◽

Marek Pawelczyk ◽

Li Cheng

Keyword(s):

Noise Control ◽

Moment Of Inertia ◽

Control Applications ◽

Mass Moment ◽

Mass Moment Of Inertia

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Modeling and validation of crankshaft speed fluctuations of a single-cylinder four-stroke diesel engine

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/09544070211026290 ◽

2021 ◽

pp. 095440702110262

Author(s):

Mustafa Babagiray ◽

Hamit Solmaz ◽

Duygu İpci ◽

Fatih Aksoy

Keyword(s):

Diesel Engine ◽

Dynamic Model ◽

Moment Of Inertia ◽

Mass Motion ◽

Cylinder Pressure ◽

Motion Equations ◽

Single Cylinder ◽

Mass Moment ◽

Mass Moment Of Inertia ◽

Speed Fluctuations

In this study, a dynamic model of a single-cylinder four-stroke diesel engine has been created, and the crankshaft speed fluctuations have been simulated and validated. The dynamic model of the engine consists of the motion equations of the piston, conrod, and crankshaft. Conrod motion was modeled by two translational and one angular motion equations, by considering the kinetic energy resulted from the mass moment of inertia and conrod mass. Motion equations involve in-cylinder gas pressure forces, hydrodynamic and dry friction, mass inertia moments of moving parts, starter moment, and external load moment. The In-cylinder pressure profile used in the model was obtained experimentally to increase the accuracy of the model. Pressure profiles were expressed mathematically using the Fourier series. The motion equations were solved by using the Taylor series method. The solution of the mathematical model was performed by coding in the MATLAB interface. Cyclic speed fluctuations obtained from the model were compared with experimental results and found compitable. A validated model was used to analyze the effects of in-cylinder pressure, mass moment of inertia of crankshaft and connecting rod, friction, and piston mass. In experiments for 1500, 1800, 2400, and 2700 rpm engine speeds, crankshaft speed fluctuations were observed as 12.84%, 8.04%, 5.02%, and 4.44%, respectively. In simulations performed for the same speeds, crankshaft speed fluctuations were calculated as 10.45%, 7.56%, 4.49%, and 3.65%. Besides, it was observed that the speed fluctuations decreased as the average crankshaft speed value increased. In the simulation for 157.07, 188.49, 219.91, 251.32, and 282.74 rad/s crankshaft speeds, crankshaft speed fluctuations occurred at rates of 10.45%, 7.56%, 5.84%, 4.49%, and 3.65%, respectively. The effective engine power was achieved as 5.25 kW at an average crankshaft angular speed of 219.91 rad/s. The power of friction loss in the engine was determined as 0.68 kW.

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