Fernández Sánchez, Julio Juan2025-06-062025-06-062025-05-16Fernández, J.J. Optimization of heat engines with fixed heat fluxes at the hot or the cold side. Eur. Phys. J. Plus 140, 401 (2025). https://doi.org/10.1140/epjp/s13360-025-06395-w2190-5444https://doi.org/10.1140/epjp/s13360-025-06395-whttps://hdl.handle.net/20.500.14468/26877This is the Accepted Manuscript of an article published by Springer in "The European Physical Journal Plus, vol 140" on May 2025, available online: https://doi.org/10.1140/epjp/s13360-025-06395-w Este es el manuscrito aceptado de un artículo publicado por Springer en "The European Physical Journal Plus, vol 140" en mayo 2025, disponible en línea: https://doi.org/10.1140/epjp/s13360-025-06395-wWe use the low dissipation model to optimize the power of heat engines in which the total amount of energy taken from the hot reservoir is kept fixed while the total amount of energy dissipated to the cold reservoir is optimizable. Then, we optimize heat engines working while they reject fixed amounts of energy to the cold reservoir. We find that under these operating conditions, the maximum power and efficiency at maximum power are different from those of thermal engines that are optimized without imposing restrictions. For both working situations, we analyze the effect that small perturbations changing the value of the fixed heat (on the hot or cold side) have on the heat engine work, efficiency, and power.eninfo:eu-repo/semantics/openAccess24 Ciencias de la Vidajournal article