Fig. 5 Comparison of the changes of Tmax among case 1 to case 3
On the other hand, in case 2, the first and second term decrease due to the increase of G1 caused by the increase of ps/pme and also by the increase of V1/VH, as the results, T4 decease totally in spite of the increasing effect due to the decrease of ηth and ε.
3.3 Change of Tmax on the layout diagram
As already mentioned before, the engine manufactures have their own planning diagram of ps/pme. which increases gradually along with the decrease of pme/pme0 in order to avoid the increase of Tmax0. In order to confirm this fact, three types of the engines of A, C and G were selected as the representative engine of the three groups, and the change on Tmax were calculated according to the planning diagram of ps/pme in the area of pme/pme0 of 1.0〜0.8 in the layout diagram. The results are shown in Fig. 6.
The figure (a) in Fig. 6 shows the setting values of pmax/pme, which increase in inversely proportional to the decrease of pme/pme0 because of pmax being set constant. The figure (b) shows the planning diagram of ps/pme. The values of the slope of ps/pme against pme/pme0 are -0.101 to -0.118, and the mean value of them is -0.11.
When pmax/pmax0 and ps/pme are set as mentioned above, V1/VH and V2/VH are determined as shown in figure (c) and (d) according to the already mentioned matching method. The changes of Tmax/Tmax0 due to the above mentioned parameter changes are shown in figure (e). For reference, the calculation results under the constant ps/pme are also shown in this figure.
