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The purpose of this paper is to study the laminar boundary layer flow between a stationary nonporous disk and a porous rotating disk, both being immersed in large amount of fluid.

The governing nonlinear momentum equations in cylindrical polar coordinates together with relevant boundary conditions are reduced to a system of coupled nonlinear ordinary differential equations (NODEs) using similarity transformations. The resulting coupled NODEs are solved using computer-extended series solution and homotopy analysis method.

The analytical solutions are explicitly expressed in terms of recurrence relation for determining the universal coefficients. The nature and location of singularity which restricts the convergence of series is analyzed by using Domb–Sykes plot. Reversion of series is used for the improvement of series. The region of validity of series is extended for much larger values of Reynolds number (R), i.e. R = 6 to 15.

The resulting solutions are compared with earlier works in the literature and are found to be in good agreement.

Choosing the best bid is a central step in any tendering process. If the award criterion is the economically most advantageous tender (EMAT), this involves scoring bids on price and quality and ranking them. Scores are calculated using a bid evaluation formula that takes as inputs price and quality, and their respective weights. The choice of formula critically affects which bid wins. We study 38 such formulas and discuss several of their aspects, such as how much the outcome of a tender depends on which formula is being used, relative versus absolute scoring, ranking paradox, iso-utility curves, protection against a winner with an extremely high price, and how a formula reflects the weights of price and quality. Based on these analyses, we summarize the (dis)advantages and risks of certain formulas and provide associated warnings when applying certain formulas in practice.