Spectral Approximation of an Oldroyd Liquid Draining down a Porous Vertical Surface

Table 1

𝑁 (number of modes)	log10(error) impermeable wall	log10(error) permeable wall (𝛼=1)
10	−5.1	−5.3
15	−6.45	−6.55
20	−7.12	−7.14