scholarly journals Development, Evolution, and Assessment of a Momentum-Variable-Based Procedure for the Prediction of Flow at All Speeds

2016 ◽  
Author(s):  
G. E. Schneider
Keyword(s):  
Momentum Variable ◽  
All Speeds

An analogy-based momentum-variable procedure for flow at all speeds

1997 ◽  
Author(s):  
M. Darbandi ◽  
G. Schneider ◽  
M. Darbandi ◽  
G. Schneider
Keyword(s):  
Momentum Variable ◽  
All Speeds

Experimental Evaluation of Turbo-Matching Appropriateness of B60J67, B60J68, A58N70 and A58N72 Turbo-Chargers for a Commercial Vehicle Engine

2018 ◽  
Vol 6 (11) ◽  
pp. 71
Author(s):  
Badal Dev Roy ◽  
R. Saravanan
Keyword(s):  
Internal Combustion Engines ◽  
Perfect Match ◽  
Engine Performance ◽  
Operating Conditions ◽  
Data Logger ◽  
Negative Effects ◽  
Road Test ◽  
The Road ◽  
A Charge ◽  
All Speeds

The Turbocharger is a charge booster for internal combustion engines to ensure best engine performance at all speeds and road conditions especially at the higher load.  Random selection of turbocharger may lead to negative effects like surge and choke in the breathing of the engine. Appropriate selection or match of the turbocharger (Turbomatching) is a tedious task and expensive. But perfect match gives many distinguished advantages and it is a one time task per the engine kind. This study focuses to match the turbocharger to desired engine by simulation and on road test. The objective of work is to find the appropriateness of matching of turbochargers with trim 67 (B60J67), trim 68 (B60J68),  trim 70 (A58N70) and trim 72 (A58N72) for the TATA 497 TCIC -BS III engine. In the road-test (data-logger method) the road routes like highway and slope up were considered for evaluation. The operating conditions with respect various speeds, routes and simulated outputs were compared with the help of compressor map.

Momentum variable procedure for solving compressible and incompressible flows

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1801-1805
Author(s):  
M. Darbandi ◽  
G. E. Schneider
Keyword(s):  
Incompressible Flows ◽  
Momentum Variable

scholarly journals An interface-aware sub-scale dynamics multi-material cell model for solids with void closure and opening at all speeds

2020 ◽  
Vol 208 ◽  
pp. 104578
Author(s):  
Matej Klima ◽  
Andrew Barlow ◽  
Milan Kucharik ◽  
Mikhail Shashkov
Keyword(s):  
Cell Model ◽  
Void Closure ◽  
All Speeds

Friction Analysis on Vane of an Existing and of a Novel Multi Vane Rotary Compressor

2013 ◽  
Vol 284-287 ◽  
pp. 763-767
Author(s):  
A.R. Sarip ◽  
M.N. Musa
Keyword(s):  
The Other ◽  
Rotary Compressor ◽  
Brushless Dc Motor ◽  
Dramatic Reduction ◽  
Brushless Dc ◽  
Inner Surface ◽  
Instantaneous Pressure ◽  
All Speeds ◽  
Friction Analysis ◽  
Angle Of Rotation

This paper presents results of a frictional analysis on a new rotating sleeve multi-vane rotary (RSMVR) compressor. The new five-vane rotary compressor is adapted from the existing concept of a rotating sleeve single-vane rotary (RSSVR) compressor, in which the extended rounded end of one vane is embedded into the inner surface of the sleeve which allows the vane to swing within a certain small angle. As the rotor rotates, this vane drives the sleeve which in turn pushes and pulls the vane into and out of the slot in the rotor, respectively. The other four vanes are similarly pushed into the respective slots in the rotor but slide out only when a sufficient centrifugal force is developed. The driving vane ensures that suction, compression and discharge of the gas occur at all speeds of rotation. Although the sleeve rotates along, due to eccentricity between the rotor and the sleeve, each tip of the four vanes still rubs against the inner surface of the sleeve. The focus of the present study limits its analysis on to only frictions between the vane tip and the inner surface of the sleeve and between the vane sides and the respective slot walls. The frictional analysis is carried out by first determining the instantaneous pressure inside the compression cell and all the associated forces that exist. This involves an analysis on the dynamics of each vane when it reciprocates and at the same time rotates eccentrically with the sleeve. The kinematics of the vane are modelled using cosine and sine rules taking the cell leading vane as a reference to the angle of rotation. In the operation the model estimates a dramatic reduction in friction which is up to 82% lower than that occurs in an existing design of an equivalent conventional multi-vane rotary compressor (MVR). A friction between the rotating sleeve and the two opposite end plates exists in the RSMVR compressor but does not in that of the MVR. This will be included in a later study but on a new integrated brushless DC motor RSMVR compressor concept and on that of the existing shaft driven MVR, to see the overall difference in the frictions exerted.

scholarly journals Associations Between Foot Placement Asymmetries and Metabolic Cost of Transport in Hemiparetic Gait

2016 ◽  
Vol 31 (2) ◽  
pp. 168-177 ◽  
Author(s):  
James M. Finley ◽  
Amy J. Bastian
Keyword(s):  
Walking Speed ◽  
Metabolic Cost ◽  
Positive Association ◽  
Stroke Survivor ◽  
Gas Analysis ◽  
Stroke Survivors ◽  
Cost Of Transport ◽  
Foot Placement ◽  
Hemiparetic Gait ◽  
All Speeds

Stroke survivors often have a slow, asymmetric walking pattern. They also walk with a higher metabolic cost than healthy, age-matched controls. It is often assumed that spatial-temporal asymmetries contribute to the increased metabolic cost of walking poststroke. However, elucidating this relationship is made challenging because of the interdependence between spatial-temporal asymmetries, walking speed, and metabolic cost. Here, we address these potential confounds by measuring speed-dependent changes in metabolic cost and implementing a recently developed approach to dissociate spatial versus temporal contributions to asymmetry in a sample of stroke survivors. We used expired gas analysis to compute the metabolic cost of transport (CoT) for each participant at 4 different walking speeds: self-selected speed, 80% and 120% of their self-selected speed, and their fastest comfortable speed. We also computed CoT for a sample of age- and gender-matched control participants who walked at the same speeds as their matched stroke survivor. Kinematic data were used to compute the magnitude of a number of variables characterizing spatial-temporal asymmetries. Across all speeds, stroke survivors had a higher CoT than controls. We also found that our sample of stroke survivors did not choose a self-selected speed that minimized CoT, contrary to typical observations in healthy controls. Multiple regression analyses revealed negative associations between speed and CoT and a positive association between asymmetries in foot placement relative to the trunk and CoT. These findings suggest that interventions designed to increase self-selected walking speed and reduce foot-placement asymmetries may be ideal for improving walking economy poststroke.

The effect of training on the swimming muscles of the goldfish (Carassius auratus)

1978 ◽  
Vol 74 (1) ◽  
pp. 115-122 ◽  
Author(s):  
W. Davison ◽  
G. Goldspink
Keyword(s):  
Carassius Auratus ◽  
Chemical Constituents ◽  
Water Environment ◽  
Muscle Fibres ◽  
Muscle Fibre Size ◽  
Goldfish Carassius Auratus ◽  
High Speeds ◽  
Major Chemical ◽  
All Speeds ◽  
Rates Of Growth

Goldfish (Carassius auratus) were exercised continuously for periods of 28 days at swimming speeds of 1.5, 3.0 and 4.5 body lengths per second and their rates of growth were determined. Changes in muscle fibre size were examined, as were changes which occurred in the concentrations of the major chemical constituents of these cells. These fish, typical of the carp family in that they are found only in still or slowly moving water, did not adapt well to the flowing water environment at any swimming speed. They often grew less than the controls, although consuming much more food. Changes in the composition of the muscle fibres indicated that excess food was not being stored, and also indicated that the major fuel for swimming at all speeds was glycogen. The fish survived well at high speeds and it was suggested that this was due to the ability of the species to metabolize glycogen anaerobically without the production of lactic acid.

Energy Expenditure of Level Overground Walking in Young Adults: Comparison With Prediction Equations

2021 ◽  
pp. 1-8
Author(s):  
Jingjing Xue ◽  
Shuo Li ◽  
Rou Wen ◽  
Ping Hong
Keyword(s):  
Young Adults ◽  
Energy Expenditure ◽  
Metabolic Rate ◽  
Energy Cost ◽  
Sports Medicine ◽  
Resting Metabolic Rate ◽  
Prediction Equations ◽  
Overground Walking ◽  
All Speeds ◽  
Walking Energy Cost

Background: The purpose of this study was to investigate the accuracy of the published prediction equations for determining level overground walking energy cost in young adults. Methods: In total, 148 healthy young adults volunteered to participate in this study. Resting metabolic rate and energy expenditure variables at speeds of 4, 5, and 6 km/h were measured by indirect calorimetry, walking energy expenditure was estimated by 3 published equations. Results: The gross and net metabolic rate per mile of level overground walking increased with increased speed (all P < .01). Females were less economical than males. The present findings revealed that the American College of Sports Medicine and Pandolf et al equations significantly underestimated the energy cost of overground walking at all speeds (all P < .01) in young adults. The percentage mean bias for American College of Sports Medicine, Pandolf et al, and Weyand et al was 12.4%, 16.8%, 1.4% (4 km/h); 21.6%, 15.8%, 7.1% (5 km/h); and 27.6%, 12%, 6.6% (6 km/h). Bland–Altman plots and prediction error analysis showed that the Weyand et al was the most accurate in 3 existing equations. Conclusions: The Weyand et al equation appears to be the most suitable for the prediction of overground walking energy expenditure in young adults.

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