An Approximate Method for Estimating the Critical Reynolds Number for a Heated Flat Plate in Water
Presents a method for estimating critical Reynolds number for a heated flat plate water boundary layer. This method allows predictions without a computer, and with surprising accuracy. The simplicity and accuracy of the method suggest exploiting the techniques in a low drag design optimization scheme. The primary idea behind the method is that a boundary-layer velocity profile can be represented as accurately as desired using a series solution derived from the exact differential equations. This series solution depends on two unknown parameters, wall shear and heat transfer. Simplified but non-conventional integral solutions of both momentum and energy equations provide accurate estimates of these parameters. Employing the resulting velocity profile series in the modified Dunn-Lin approximation, critical Reynolds can be calculated. The analysis results in closed-form expressions for shear and heat transfer. Therefore, the critical Reynolds number can be calculated with minimum computational effort.