Rotating scroll waves are dynamical spatiotemporal structures characteristic of three-dimensional active media. It is well known that, under low excitability conditions, scroll waves develop an intrinsically unstable dynamical regime that leads to a highly disorganized pattern of wave propagation. Such a "turbulent" state bears some resemblance to fibrillation states in cardiac tissue. We show ...

Mound formation in the cellular slime mould Dictyostelium results from the chemotactic aggregation of competent cells. Periodic cAMP signals propagate as multiarmed spiral waves and coordinate the movement of the cells. In the late aggregate stage the cells differentiate into prespore and several prestalk cell types. Prestalk cells sort out chemotactically to form the tip, which then controls a...

The scroll wraps of a scroll compressor play a very important role in the compressor’s efficiency due to their impact on leakage and leakage irreversibilities. In this work, a short summary of the scroll compressor geometry is presented. Using the geometry of the scroll wraps, an optimal scroll wrap geometry is derived for a given set of constraints on compressor displacement, scroll wrap thick...

We study entropy of chaotic oscillation of electrical currents in the Chua’s circuit controlled by triggering a pulse that brings the orbit that goes onto an unstable branch back to a stable branch. A numerical simulation of the voltage of the two capacitors and the current that flows on an inductor of the Chua’s circuit reveals various oscillation patterns as the conductance that is connected ...

Based on thermodynamic and mechanical models. the axial and tangential forces acting on the orbiting scroll and their balance methods are discussed in this paper. Besides, a detailed analysis of orbiting mechanism of three Pins is carried out too. INTRODUCTION The advantageous characteristics of scroll compressor have been pr1>ved in theory and experiment [ 1 ] [ 3 ] in rer.ent years. Remarking...

The efficiency of the scroll compressor which employs the axial and the radial sealing techniques is competitive with that of the other rotary and the reciprocating compressors. The bearing load and the torque are smooth so that quiet operation is realized. 'l'herefore the machine is suitable particularly for air conditioning application. The authors have studied the scroll compressor which uti...

Experimental results are presented on the effect of coupling on synchronization of two coupled nonidentical Chua’s oscillators. Two oscillators are coupled in unidirectional drive response mode. The driver is always kept in chaotic ~single scroll, double scroll! state while the response oscillator is kept in various dynamical states as point attractor, single scroll periodic, chaotic and double...

This paper describes the efficiency improvement technology of the 3D scroll compressors and the development of 3D scroll compressor for commercial air-conditioner. 3D scroll, our newly developed profile, can compress refrigerant not only radially but also axially. Therefore, higher compression ratio, higher reliability and larger capacity are obtained by introducing 3D scroll. Since the 3D scro...