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We perform a series of numerical simulations to recreate small-scale two-fluid jets using the JOANNA code, considering the magnetohydrodynamics of two fluids (ions + electrons and neutral particles). We first excite the jets in a uniform magnetic field by using velocity pulse perturbations located at $y_{0}=$1.3, 1.5, and 1.8 Mm, considering the base of the photosphere at $y=0$ Mm. Then, we repeat the excitation of the jets in a magnetic field that mimics a flux tube. Mainly, the jets excited at the upper chromosphere ($y\sim1.8$ Mm) reach lower heights than those excited at the lower chromosphere ($y\sim1.3$ Mm); this is due to the higher initial vertical location because of the lesser amount of plasma dragging. In both scenarios, the dynamics of the neutral particles and ions show similar behavior; however, we can still identify some differences in the velocity drift, which in our simulations is of the order of $10^{-3}$ km s$^{-1}$ at the tips of the jets once they reached their maximum heights. Also, we estimate the heat generation due to the friction between ions and neutrals ($Q^{in}_{i,n}$), which is of the order of $0.002-0.06$ W m$^{-3}$; however it is small to contribute to the heating of the surroundings of the solar corona. The jets in the two magnetic environments do not show substantial differences other than a slight variation in the maximum heights reached, particularly in the uniform magnetic field scenario. Finally, the maximum heights reached by the three different jets are in the range of some morphological parameters corresponding to macrospicules, Type I spicules, and Type II spicules., Comment: 15 pages, 6 figures. Accepted for publication in Physics

In this work we present three energy converters which have the same efficiency under certain optimum conditions of performance. The first one is the well-known Curzon-Ahlborn finite-time heat engine. The second one is an infinitetime cycle operating between two thermal bodies with finite heat capacities. The last case is a water mixer working as engine, which is designed with two stationary fluxes of water at different temperatures, T1 and T2, with only one exit, at temperature T, the specific heat capacity, c, is considered as a constant., En este trabajo se presentan tres diferentes convertidores de energia que tienen la misma eficiencia bajo ciertas condiciones optimas de operacion. El primero se trata de la ampliamente conocida maquina de Curzon-Ahlborn operando a tiempo finito. El segundo se trata de una sucesion de ciclos de Carnot operando entre dos cuerpos termicos con capacidad calorifica finita. El ultimo caso es una mezcladora de agua trabajando como maquina, la cual esta disenada con la entrada de dos flujos estacionarios de agua a diferentes temperaturas, T1 y T2, con una sola salida, a temperatura T, con calor especifico, c, que se toma como constante.

In this work we present three energy converters which have the same efficiency under certain optimum conditions of performance. The first one is the well-known Curzon-Ahlborn finite-time heat engine. The second one is an infinitetime cycle operating between two thermal bodies with finite heat capacities. The last case is a water mixer working as engine, which is designed with two stationary fluxes of water at different temperatures, T1 and T2, with only one exit, at temperature T, the specific heat capacity, c, is considered as a constant., En este trabajo se presentan tres diferentes convertidores de energia que tienen la misma eficiencia bajo ciertas condiciones optimas de operacion. El primero se trata de la ampliamente conocida maquina de Curzon-Ahlborn operando a tiempo finito. El segundo se trata de una sucesion de ciclos de Carnot operando entre dos cuerpos termicos con capacidad calorifica finita. El ultimo caso es una mezcladora de agua trabajando como maquina, la cual esta disenada con la entrada de dos flujos estacionarios de agua a diferentes temperaturas, T1 y T2, con una sola salida, a temperatura T, con calor especifico, c, que se toma como constante.

In this work we present three energy converters which have the same efficiency under certain optimum conditions of performance. The first one is the well-known Curzon-Ahlborn finite-time heat engine. The second one is an infinitetime cycle operating between two thermal bodies with finite heat capacities. The last case is a water mixer working as engine, which is designed with two stationary fluxes of water at different temperatures, T1 and T2, with only one exit, at temperature T, the specific heat capacity, c, is considered as a constant., En este trabajo se presentan tres diferentes convertidores de energia que tienen la misma eficiencia bajo ciertas condiciones optimas de operacion. El primero se trata de la ampliamente conocida maquina de Curzon-Ahlborn operando a tiempo finito. El segundo se trata de una sucesion de ciclos de Carnot operando entre dos cuerpos termicos con capacidad calorifica finita. El ultimo caso es una mezcladora de agua trabajando como maquina, la cual esta disenada con la entrada de dos flujos estacionarios de agua a diferentes temperaturas, T1 y T2, con una sola salida, a temperatura T, con calor especifico, c, que se toma como constante.