GT-Power建模中遇到的问题.doc

TY3100EZ增压柴油机整机性能循环模拟研究 GT—POWER建模中遇到的和应该注意的问题 OrificeConn的应用 在两根管道连接时，如果连接处两根管的管径不相同而且是光滑连接时，此时应该应用“bellmouth”模块，只是里面的值设置成为默认值即可。 Typical values are 0.6 for a small diameter orifice between two large diameter pipes, 0.8 for a connection between a large diameter to a much smaller diameter (when the diameter ratio is 10:1 and only in the direction of large to small) and 1.0 for situations where the orifice area and the pipe area are the same. To indicate a rounded inlet from either side, the user has to input value close to 1.0. If there is no diameter restriction, “def” (default) may be entered for the orifice diameter and the code will use the smaller diameter of the two mating components as the orifice diameter. Wall Temperature的取值 总体上说，这一值应该根据经验。在进气系统一般设置能环境温度，而在排气系统中则根据排气温度来设置。 进、排气系统管路中的特征长度和膨胀直径要通过三维离散得到。 离散过程相关内容见用户指导教程中的Tutorial 10: 3D-Discretization Tool。工具中操作的具体含义见用户手册。（特别注意：导入3D-Discretization Tool中的STL文件是用三维建模软件生成的。） 管接头每个接头角度的设置 参照一个方向设置，相关内容参见培训教程。在进、排气系统中管接头的和管道的相关参数是通过对整个系统进行离散化而得到的。 Compressors may have any number of flow inlets, but only one flow outlet. Pipe* and Fsplit* components should only be connected to compressors by default (def) orifices. (If an orifice that is not made from the def object is used, its attributes will be ignored by the code in effect making it a def orifice.) The compressors flow outlet must always have its port number set to zero, but the inlet port numbers can be any arbitrary integer larger than zero. 在建立整机模型时，应该在每一个外接部件建立后进行计算，然后查看计算结果和试验结果相差多少（主要是看质量流量），如果相差在2%～3%范围内，则认为所建模型是正确的，模型里的参数的选取是合理的，然后建立其他部件的模型。如果超过这个范围，则要调整参数，重新计算。比如在建立增压中冷的模型过程中，先建立中冷器，计算、查看结果、调整，然后建立压气机，计算、查看结果、调整，再建立涡轮机的模型，计算、查看结果、调整。最后才是压气机和涡轮机的连接，整机计算。这样做的目的是为了当计算结果和试验结果相差较大时，方便检查、调整参数。 Maps: 在增压器的建模过程中注意：The maps must be preprocessed before they can be used in the engine model because (1)measurement errors may cause the data to be poorly shaped, (2)the data may be very sparse and may need to be “filled in” between the available data points, and (3)th