Determination of the Engineering Properties of Aerial Yam and Water Yam

Abstract

This research presents the determination of some engineering properties (shear stress, hardness, modulus of elasticity, compressive strength, deformation at the break, bio-yield, rupture energy, gumminess, specific heat capacity, thermal diffusivity, and thermal conductivity) of water yam and aerial yam. The water yam and aerial yam were dried with the conventional hot air dryer. Using approved standard methods and instruments, experimental determination of the mechanical and thermal properties of the dried water yam (DWY), dried aerial yam (DAY), raw water yam (RWY) and raw aerial yam (RAY) were conducted and results obtained. The result showed the mechanical properties of DWY, DAY, RWY and RAY fell within the range of 1.803-6.63 N/mm2 for shear strength, 15.582-31.977 N for hardness, 87.5-400N for bio-yield force, 1.256-4.699 J for rupture energy, 2.788- 36.829 N/mm2 for modulus of elasticity, 1.815-7.5 N for deformation at break, 0.501-2.688 N/mm2 for compressive strength and 4.975-19N for gumminess. The thermal properties showed the following ranges: specific heat capacity value of 1.55-3.21 KJ/kgK the thermal conductivity of 0.256-0.473 W/mK and the thermal diffusivity of 1.280x10-4 - 1.50x10-4 m2/s. The result provides a theoretical basis and data for the design of aerial yam and water yam processing equipment while minimizing its mechanical damage.