Mathematical modeling and comparison of air standard Dual and Dual-Atkinson cycles with friction, heat transfer and variable specific-heats of the working fluid

Progress in Finite Time Thermodynamic Studies for Internal Combustion Engine Cycles

“…The third is to adopt more comprehensive and effective OPBs in the analysis and optimization of ICE performance, especially, multi-objective optimization procedures will be utilized. [85,223,323,324], Dual-Miller combined cycle [215,325,326] and Otto-Miller combined cycle [327]. The second is to establish new cycle models which are closer to practical cycles.…”

“…In the future, the analysis and optimization of ICE cycles by using FTT can further progress in the following aspects: the first is to perform FTT performance analysis and optimization for various new single cycles and combined reciprocating cycles, such as the Meletis-Georgiou cycle ( Figure 18 shows the T´s diagrams for Meletis-Georgiou cycle model, the isentropic compression processes are shown as 1 Ñ 2S and 3 Ñ 4S; the process of mixing between the working fluid at state 2 with part of the expanding working fluid at state 6 is shown as process 2 Ñ 3; the isochoric heat addition process is 4 Ñ 5; the isentropic expansion processes are shown as 5 Ñ 6S and 7S Ñ 8S; the separation process of the working fluid in expansion volume is shown as 6 Ñ 7; the isochoric and isobaric heat rejection processes are shown as 8 Ñ 9 and 9 Ñ 1) [303][304][305][306][307][308][309], rectangular cycle ( Figure 19 shows p´v diagram for the rectangular cycle model, the isochoric and isobaric heat addition processes are shown as 1 Ñ 2 and 2 Ñ 3; the isochoric and isobaric heat rejection are shown as 3 Ñ 4 and 4 Ñ 1) [310][311][312][313][314][315][316], Lenoir cycle ( Figure 20 shows T´s diagram for the Lenoir cycle model, the isochoric heat addition process is shown as 1 Ñ 2; the isentropic expansion processes is shown as 2 Ñ 3; the isobaric heat rejection is shown as 3 Ñ 1) [317][318][319][320][321][322], Dual-Atkinson combined cycle [85,223,323,324], Dual-Miller combined cycle [215,325,326] and Otto-Miller combined cycle [327]. The second is to establish new cycle models which are closer to practical cycles.…”

“…Considering HTL and FL, Lin [222] used the model of linear SH variation as a function of the temperature in [88,218], derived the power output and efficiency performance characteristics of an irreversible Dual cycle, and investigated the influences of the two losses and VSH on cycle performance. Using the model of SH variation as a linear function of temperature in [88,[218][219][220][221][222], Gahruei et al [223] studied the power output and efficiency performance characteristics of an irreversible Dual cycle and an irreversible Dual-Atkinson cycle with HTL and FL considered, investigated the influences of VSH, and the two losses on cycle performances, compared the performances of the two cycles, and found that the performance of the Dual-Atkinson cycle is higher than that of an irreversible Dual cycle.…”

“…Considering HTL, FL and IIL and fixing the cycle maximum temperature, Ge [84] used the VSH model established in [88,96,[218][219][220][221][222][223] to study the optimum EF performance of an irreversible Dual cycle, and analyzed the influences of the three losses and VSH on cycle EF performance. Considering HTL, FL and IIL and fixing the cycle maximum temperature, Ge et al [84,224] adopted the VSH model advanced in [85][86][87][88], and investigated the optimum power and efficiency performance [84,224], as well as the optimum EF performance [84] of an irreversible Dual cycle, and examined the influences of the three losses on cycle optimum performance.…”

Effect of Volume Ratio of Heat Rejection Process on Performance of an Atkinson Cycle

“…The performance characteristics of six endoreversible heat engines, including Carnot, Diesel, Otto, Atkinson, Brayton and Dual cycles is studied by Ding et al [14]. Gahruei et al [15] carried out a comparative performance analysis for classical dual and dual-Atkinson cycles based on finite-time thermodynamics, taking into account variable specific heats of the working fluid and the losses resulting from heat transfer and frictions. Ebrahimi [16] derived the power output and the thermal efficiency performance characteristics of an irreversible Atkinson cycle, investigated the influence of air-fuel ratio, fuel mass flow rate and residual gas on cycle performance, and found that the performances would increase with increase in air-fuel ratio and residual gas when the compression ratio was less than certain value, the performances would decrease with increase in air-fuel ratio and residual gas when the compression ratio exceeded certain value, and the performance would increase with increase in fuel mass flow rate throughout the compression ratio working range.…”