TY  - EJOU
AU  - Islam, Mujahid 
AU  - Ali, Fateh 
AU  - Feng, Xinlong 
AU  - Zahid, M. 
AU  - Maqbool, Sana Naz 

TI  - Optimization and Sensitivity Analysis of Non-Isothermal Carreau Fluid Flow in Roll Coating Systems with Fixed Boundary Constraints: A Comparative Investigation
T2  - Computer Modeling in Engineering \& Sciences

PY  - 2025
VL  - 145
IS  - 3
SN  - 1526-1506

AB  - Roll coating is a vital industrial process used in printing, packaging, and polymer film production, where maintaining a uniform coating is critical for product quality and efficiency. This work models non-isothermal Carreau fluid flow between a rotating roll and a stationary wall under fixed boundary constraints to evaluate how non-Newtonian and thermal effects influence coating performance. The governing equations are transformed into non-dimensional form and simplified using lubrication approximation theory. Approximate analytical solutions are obtained via the perturbation technique, while numerical results are computed using both the finite difference method and the BVP-Midrich technique. Furthermore, Response surface methodology (RSM) is employed for optimization and sensitivity analysis. Analytical and numerical results show strong agreement (&lt;1% deviation). The model predicts coating thickness <mml:math id="mml-ieqn-1"><mml:mn>0.55</mml:mn><mml:mo>≤</mml:mo><mml:mi>λ</mml:mi><mml:mo>≤</mml:mo><mml:mn>0.64</mml:mn></mml:math>, power input <mml:math id="mml-ieqn-2"><mml:mn>1.05</mml:mn><mml:mo>≤</mml:mo><mml:msub><mml:mi>P</mml:mi><mml:mrow><mml:mi>w</mml:mi></mml:mrow></mml:msub><mml:mo>≤</mml:mo><mml:mn>1.99</mml:mn></mml:math>, and separation force <mml:math id="mml-ieqn-3"><mml:mn>0.91</mml:mn><mml:mo>≤</mml:mo><mml:msub><mml:mi>S</mml:mi><mml:mrow><mml:mi>f</mml:mi></mml:mrow></mml:msub><mml:mo>≤</mml:mo><mml:mn>1.82</mml:mn></mml:math> for <mml:math id="mml-ieqn-4"><mml:mn>0.1</mml:mn><mml:mo>≤</mml:mo><mml:mi>W</mml:mi><mml:mi>e</mml:mi><mml:mo>≤</mml:mo><mml:mn>0.9</mml:mn></mml:math> and <mml:math id="mml-ieqn-5"><mml:mn>0.01</mml:mn><mml:mo>≤</mml:mo><mml:mi>F</mml:mi><mml:mo>≤</mml:mo><mml:mn>0.09</mml:mn></mml:math>. Increasing <mml:math id="mml-ieqn-6"><mml:mi>W</mml:mi><mml:mi>e</mml:mi></mml:math> enhances the coating thickness and power input but reduces velocity and separation force. The findings provide physical insight into elastic and viscous effects in roll coating, providing insight for optimizing coating uniformity, minimizing wear, improving industrial coating processes, and extending substrate lifespan.
KW  - Roll coating process; finite difference method; carreau fluid model; sensitivity analysis; response surface methodology; lubrication theory

DO  - 10.32604/cmes.2025.073678