3 F eb 1 99 9 Feynman ’ s ratchet and pawl : an exactly solvable model

Feynman's ratchet and pawl: an exactly solvable model.

We introduce a simple, discrete model of Feynman's ratchet and pawl, operating between two heat reservoirs. We solve exactly for the steady-state directed motion and heat flows produced, first in the absence and then in the presence of an external load. We show that the model can act both as a heat engine and as a refrigerator. We finally investigate the behavior of the system near equilibrium,...

X iv : c on d - m at / 0 50 65 43 v 1 [ co nd - m at . o th er ] 2 1 Ju n 20 05 Ratchet , Pawl and Spring Brownian Motor

We present a model for a thermal Brownian motor based on Feynman’s famous ratchet and pawl device. Its main feature is that the ratchet and the pawl are in different thermal baths and connected by an harmonic spring. We simulate its dynamics, explore its main features and also derive an approximate analytical solution for the mean velocity as a function of the external torque applied and the te...

Computer simulation of Feynman's ratchet and pawl system.

In this work, we introduce two models of Feynman's ratchet and pawl system. Molecular dynamics is carried out to simulate the two designs for Feynman's ratchet and pawl systems followed by a Langevin dynamics simulation of the reduced system. We find that the ratchet will rotate as designed when the temperature of the pawl chamber is lower than that of the ratchet chamber, which is consistent w...

ep - p h / 95 02 20 3 v 1 1 F eb 1 99 5 Implications of Electroweak Precision Tests ∗ † Dieter Schildknecht

The Problem of Detailed Balance for the Feynman-Smoluchowski Engine (FSE) and the Multiple Pawl Paradox

The Feynman-Smoluchowski Engine (FSE) is simply a ratchet and pawl device, connected by a shaft to a vane, that is small enough to rectify the effect of random bombardment of gas molecules on the vane. The significance of the FSE is that it has inspired much activity in the area of Brownian ratchets. There is considerable interest in both the FSE and Brownian ratchets as these models are findin...