Performance representation of variable-speed compressor for inverter air conditioners based on experimental data

2004 ◽  
Vol 27 (8) ◽  
pp. 805-815 ◽  
Author(s):  
Shuangquan Shao ◽  
Wenxing Shi ◽  
Xianting Li ◽  
Huajun Chen
Keyword(s):  
Experimental Data ◽  
Variable Speed ◽  
Air Conditioners

scholarly journals An Analytical Model for Demand Response of Variable-Speed Air Conditioners

2018 ◽  
Vol 51 (28) ◽  
pp. 426-431 ◽  
Author(s):  
Berend Jan Christiaan van Putten ◽  
Nariman Mahdavi ◽  
Julio H. Braslavsky
Keyword(s):  
Analytical Model ◽  
Demand Response ◽  
Variable Speed ◽  
Air Conditioners

Helmholtz Absorbers: Experiments in Controlling Resonant Pulsation Without the Use of Orifice Plates

2007 ◽  
Author(s):  
Eugene L. Broerman ◽  
Mitchel A. Smolik ◽  
Christine M. Scrivner
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
High Speed ◽  
Side Branch ◽  
Reciprocating Compressor ◽  
Variable Speed ◽  
Ancient Greek ◽  
Self Tuning ◽  
Recording Studios

Pressure drop has been used for more than half a century to control resonant pulsation in reciprocating compressor piping. Although avoiding these resonances is the preferred method, this is not possible in many high-speed/variable-speed installations. In these cases, resonant pulsation is often managed by using orifice plates to dampen the response. Helmholtz absorbers are an old technology, used to improve the acoustics of ancient Greek theaters and modern recording studios alike. Although their application in the field of piping acoustics has been well documented, this paper presents new ways in which they have not yet been applied. In this paper, experimental data is shown for a self-tuning Helmholtz absorber, or Side Branch Absorber (SBA) used to cancel a piping length resonance, and for a Virtual Orifice that is used to reduce cylinder nozzle pulsation. These devices open up new doors for controlling pulsation with reduced horsepower costs in reciprocating compressor installations.

scholarly journals Impact of Variable Speed on Collective Movement of Animal Groups

2021 ◽  
Vol 9 ◽  
Author(s):  
Pascal P. Klamser ◽  
Luis Gómez-Nava ◽  
Tim Landgraf ◽  
Jolle W. Jolles ◽  
David Bierbach ◽  
...  
Keyword(s):  
Experimental Data ◽  
Group Size ◽  
Collective Behavior ◽  
Functional Dependence ◽  
Variable Speed ◽  
Animal Groups ◽  
Agent Based ◽  
Collective Dynamics ◽  
Collective Movement ◽  
Self Organized

The collective dynamics and structure of animal groups has attracted the attention of scientists across a broad range of fields. A variety of agent-based models have been developed to help understand the emergence of coordinated collective behavior from simple interaction rules. A common, simplifying assumption of such collective movement models, is that individual agents move with a constant speed. In this work we critically re-asses this assumption. First, we discuss experimental data showcasing the omnipresent speed variability observed in different species of live fish and artificial agents (RoboFish). Based on theoretical considerations accounting for inertia and rotational friction, we derive a functional dependence of the turning response of individuals on their instantaneous speed, which is confirmed by experimental data. We then investigate the interplay of variable speed and speed-dependent turning on self-organized collective behavior by implementing an agent-based model which accounts for both these effects. We show that, besides the average speed of individuals, the variability in individual speed can have a dramatic impact on the emergent collective dynamics: a group which differs to another only in a lower speed variability of its individuals (groups being identical in all other behavioral parameters), can be in the polarized state while the other group is disordered. We find that the local coupling between group polarization and individual speed is strongest at the order-disorder transition, and that, in contrast to fixed speed models, the group’s spatial extent does not have a maximum at the transition. Furthermore, we demonstrate a decrease in polarization with group size for groups of individuals with variable speed, and a sudden decrease in mean individual speed at a critical group size (N = 4 for Voronoi interactions) linked to a topological transition from an all-to-all to a distributed spatial interaction network. Overall, our work highlights the importance to account for fundamental kinematic constraints in general, and variable speed in particular, when modeling self-organized collective dynamics.

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