[{"data":1,"prerenderedAt":52},["ShallowReactive",2],{"$f8nsj8ehte00p":3},{"slug":4,"publishedAt":5,"category":6,"title":7,"summary":8,"image":9,"imageAlt":14,"readingMinutes":15,"serviceId":16,"keywords":17,"imageCaption":21,"sections":22,"sources":48},"cfd-project-brief","2026-10-06","guides","Before CFD: define the engineering decision","What to bring to a CFD discussion: the equipment, operating envelope, available evidence and the decision the calculation must support.",{"src":10,"thumbnail":11,"width":12,"height":13},"\u002Fassets\u002Fcfd-cases\u002Fejector\u002Fimages\u002F02.webp","\u002Fbrand\u002Fstudies\u002Fejector.svg",1672,941,"DEEB-FLOW illustration of an industrial ejector and flow fields",2,"flow",[18,19,20],"CFD project brief","engineering simulation inputs","CFD boundary conditions","Concept illustration. The fields and labels do not represent measured project results.",[23,28,33,38,43],{"id":24,"title":25,"paragraphs":26},"decision","Start with a decision, not a contour plot",[27],"Which geometry should enter the next design stage? What is causing uneven flow? Will a different operating point help? State the decision and the alternatives before choosing a solver. The relevant outputs follow from that question: pressure loss, flow distribution, temperature, mixing or another quantity your team can interpret.",{"id":29,"title":30,"paragraphs":31},"inputs","Describe the equipment and its operating envelope",[32],"Bring CAD or drawings, working fluids, material data and the operating conditions you know. Distinguish measured values from estimates and identify the range of intended operation. Inlets, outlets, wall conditions and heat sources need a physical interpretation; a convenient numerical setting is not a substitute for a known operating condition.",{"id":34,"title":35,"paragraphs":36},"evidence","Separate available evidence from missing inputs",[37],"Measurements, test reports and operating observations help constrain the model. Record where measurements were taken and how the equipment was operating. When data are missing, agree on assumptions and sensitivity cases. A clear record of uncertainty is more useful than treating an uncertain input as an exact number.",{"id":39,"title":40,"paragraphs":41},"acceptance","Agree how the answer will be assessed",[42],"Specify the quantities to compare, the locations of interest and the operating cases that matter. Plan checks of convergence, balances and mesh sensitivity. If experimental data are available, define the comparison before running the model. These checks support confidence in the calculation; they do not automatically establish accuracy for every untested condition.",{"id":44,"title":45,"paragraphs":46},"deliverable","Ask for an interpretable result",[47],"An agreed deliverable can include the modelling assumptions, boundary conditions, numerical checks and comparison of alternatives, followed by conclusions and limitations. Use the first discussion to decide what evidence would change your design decision. If you only have a drawing and a problem description, start there and identify the missing inputs together.",[49],{"label":50,"href":51},"NASA \u002F NPARC: CFD analysis process","https:\u002F\u002Fwww.grc.nasa.gov\u002Fwww\u002Fwind\u002Fvalid\u002Ftutorial\u002Fprocess.html",1791759706613]