Heat exchanger designers need reliable thermal hydraulic correlations to optimize heat exchanger designs, particularly when a compact volume is desired. Current correlations for circular fin-tube bundles typically employ a flow velocity dependent term and a number of correction terms to account for geometry variations and other flow conditions. This paper evaluates five phenomena that influence thermal-hydraulic performance and discusses them in relation to current models for heat transfer and pressure drop. The varied parameters are the direction of heat flow (gas heating or gas cooling), the fin type (annular or helically wound), the fin efficiency, the fin pitch, the number of streamwise tube rows and the inlet turbulence level. A validated numerical model is used to produce Nusselt and Euler numbers for more than 30 helically wound fin-tube geometries in a staggered equilateral triangle layout. A few selected geometries are further analyzed in detail. Results indicate that a large gas-to-tube temperature difference, a low fin pitch or a high thermal effectiveness can lead to situations where some of the current models for heat transfer, pressure drop or fin efficiency perform poorly. Specifically, pressure drop is shown to be 25% higher for helical fin-tubes under gas heating conditions than for equivalent annular fin-tubes under gas cooling conditions, which is not considered by most correlations. Fin efficiencies can, further, be in error by more than 20%, which can partially be attributed to flow passing outside the fin diameter. More data is, however, needed to characterize these effects thoroughly in the general case.

换热器设计者需要可靠的热液压相关性来优化换热器设计，尤其是在需要紧凑的体积时。圆形翅片管束的当前相关性通常采用流速相关项和许多校正项，以说明几何形状变化和其他流动条件。本文评估了影响热工液压性能的五种现象，并与当前的传热和压降模型进行了讨论。变化的参数是热流的方向（气体加热或气体冷却），翅片类型（环形或螺旋缠绕），翅片效率，翅片节距，沿流方向的管排数和入口湍流度。经过验证的数值模型用于产生交错的等边三角形布局中30多个螺旋缠绕的翅片管几何形状的Nusselt和Euler数。将进一步详细分析一些选定的几何形状。结果表明，较大的气管温度差，低的翅片间距或较高的热效率会导致某些当前的传热，压降或翅片效率模型表现不佳。具体而言，在气体加热条件下，螺旋形翅片管的压降比在气体冷却条件下的等效环形翅片管的压降高25％，这在大多数相关性中都没有考虑。此外，翅片效率的误差可能超过20％，这部分归因于流过翅片直径之外的流量。但是，更多的数据是