闲着蛋疼,刚好要考六级。帮你翻译srm软件原文的简介(当然少不了google翻译的帮助啦)该软件好像来自nakka大蛇:This spreadsheet was created in order to predict the performance of a Solid Rocket Motor (SRM). Although there are many factors which make an exact prediction of actual performance difficult, it was felt that a reasonably close approximation to expected performance would be attainable, and be very useful for design purposes.这个电子表格是用来预测固体火箭发动机的性能(SRM)的。虽然有许多因素使预测确切的实际性能比较难,但合理的近似地预测性能是可以实现的,这对于设计来说非常有用。
The two most significant factors that will affect the actual (delivered) performance compared to predicted are propellant preparation and nozzle construction. Propellant preparation affects the burn rate characteristics and combustion efficiency. Care mustbe taken to have propellant constituents well-blended and of consistent oxidizer particle size (see "Conditions for Applicability", Burnrate worksheet). The nozzle efficiency can be enhanced through careful contouring and polishing of flow surfaces.
两个影响实际性能最重要的因素是推进剂的制备及喷嘴结构。推进剂会影响燃烧速度和燃烧效率。必须小心将推进剂组分完美混合。喷嘴效率可通过对喷嘴表面抛光得到加强。
Another factor that leads to inaccuracy in prediction is that the analysis assumes that ignition of the propellant occurs on all surfaces immediately and simultaneously. As well, burnout of the propellant is assumed to occur instantaneously. In reality, burning would normally initiate on those surfaces directly exposed to the ignition flame only, and as the chamber pressure rises, ignition occurs then on the remaining exposed propellant surfaces. The net affect is that the actual pressure rise and tail-off occur less rapidly than predicted, resulting in a more "rounded" shape to the pressure/timecurve.
在导致设计不准确的另一个因素是,分析中假设推进剂的点火同时发生在所有表面(内孔)。同样,推进剂是假设即时烧完。实际上,燃烧通常仅发生在点火火焰直接接触到这些表面上,随着腔内压力的上升,余下的暴露的推进剂表面随之被点着。一个影响是实际压力的上升和消失的速度低于预测,造成压力/时间曲线形状更圆。
In particular, erosive burning is difficult to model. This spreadsheet uses a simple erosive burning model, intended more for contemplative purpose than actual prediction.
实际上,烧蚀效应能以建立模型。此电子表格使用一个简单的烧蚀模式,更多地用于参考的目的而不是实际预测的目的。
Pressure and performance predictions are based upon standard thermodynamic and fluid flow equations, in conjunction with empirically obtained parameters that relate propellant burn rate to pressure. These parameters (a,n) are provided for two propellants: Potassium Nitrate/Dextrose, and Potassium Nitrate/Sorbitol, of the standard oxidizer/ fuel ratio of 65/35 (hereafter referred to as KNDX and KNSO,respectively). These particular parameters were obtained through a comprehensive series of Strand Burner measurements.
压力和性能的预测是基于标准的热力学和流体流动方程,结合经验得到如推进剂燃速与压力的关系。这些参数用于两种推进剂:硝酸钾/葡萄糖,硝酸钾/山梨糖醇,用标准的配比:氧化剂/燃料比65/35(以下分别简称为KNDX和KNSB)。
This spreadsheet is intended primarily for designing rocket motors that use KNDX and KNSO as propellants, however, other propellants may be specified, as long as the required properties are inputted by the user (see Propellant Data and Burnrateworksheets). 此电子表格的目的主要是为设计使用KNDX和KNSB作为推进剂的火箭发动机,但是,其他的推进剂也可以使用,只要用户输入所需的属性(见推进剂数据和Burnrate工作表)。
Note that this spreadsheet is solely intended for hollow-cylindrical propellant grains (including BATES). Any number of segments may be specified. The user can also specify which surfaces are to be inhibited from burning (if any).
请注意,此电子表格是专为圆内孔推进剂设计使用(包括压制型)。可以设定任意几段燃料。用户还可以指定不燃的表面(如果有)。
To provide guidance in use of this spreadsheet, and to clarify various terms, "pop up" text boxes will appear over cells with a red corner flag. These may bedisabled via the Tools/Options/View/Comments menu. 使用这种电子表格提供的帮助功能,并修改各种参数,可能会弹出一个红色的角旗形式的文本框。这可通过工具/选项/查看/批注菜单对其进行禁用。
Problems:
If the message #DIV0! appears in a calculation cell, the most likely cause is that the value of Kn that is specified is too low. In reality, this means that the burning rate of the propellant is not great enough to allow pressure to build up in the motor.(i.e. throat is too large). The solution is to change the value of Kn to a higher XXXXXXXXother problem relates to non-convergence of a solution. If this occurs, the message #NUM! will appear in a calculation cell. This can sometimes be overcome by simply quitting Excel and re-starting the application. 如果消息#DIV0!在计算值域出现,最可能的原因是Kn的指定值太低。在现实中,这意味着推进剂的燃速在这个发动机里没有造成足够的压力。(比如喷管喉口直径过大)。解决的办法是改变喷燃比到更高的数值。另一个是该问题的解决方案不对。如果发生这种情况,该消息值#NUM!将出现在计算值域。这时可以通过简单地退出Excel和重新启动应用程序克服。Please forward any comments, suggestions, or notice of problems to the author:
XXXXXXXXXXXXXXXXXXXXXt如有任何意见,建议,或问题请通知作者:
XXXXXXkka - XXXXXXXXXXXt
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