Heat loss is the most significant element reducing the overall efficiency of a solar concentrator's cavity receiver. Heat losses are measured experimentally and numerically on a cylinder with a hollow diameter of 0.35 meters, an aperture of 0.55 meters, and a wind skirt. Experiments were conducted to assess both total and convective losses at cavity angles of 0 o, 25 o, 50 o, 75 o, and 90 o. The experimental apparatus's main component is a cylinder-shaped hollow receiver insulated with glass wool. This receiver aims to limit the quantity of heat lost due to convection. A numerical investigation of the connective heat losses that occurred in the absence of wind was performed using the CFD tool. A comparison of the numerical and experimental results found good agreement, with the highest difference being 13%. When the inclination angle into the cavity receiver increases from 0o to 90o, convection and total losses decrease. It is conceivable to detect an increase in both total and convective losses when the cavity's operating temperature rises. Furthermore, M. Prakash's convective losses are compared to the current results. M. Prakash's convective loss model provides the forecast closest to matching experimental and numerical data.