Solar energy,a renewable resource,can be harnessed instead of fossil fuels to generate power and heat.One effective method for converting solar energy into heat is through a solar air heating(SAH)system.The theoretica...Solar energy,a renewable resource,can be harnessed instead of fossil fuels to generate power and heat.One effective method for converting solar energy into heat is through a solar air heating(SAH)system.The theoretical investigation focused on the thermal performance of various V-groove angles on a corrugated absorber plate.The researchers maintained the exterior dimensions and constraints of the absorber plate while increasing its surface area by using a corrugated absorber surface.For the simulation,three different V-groove angles were employed:45°,30°,and 15°.The temperature and air flow rate into the system had been set at 30℃ and 0.15 m/s,respectively four various solar radiation intensities have been examined for each of the variables.The governing equations associated with the standard design,including the turbulent kinetic energy(k)and dissipation rates model(ε),were solved using the ANSYS 2020 R2 program.The results indicated that Utilizing corrugated absorber plates resulted in a rise in the Nusselt number.,surpassing the performance of flat plate absorbers.Among the different configurations,the V-grooved 45°plate demonstrated the best results under the same conditions.Furthermore,it was observed that the efficiency values improved with increasing solar irradiance.The investigation also showed that the employing of V-grooved 45°,V-grooved 30°,and V-grooved 15°absorbers led to efficiency improvements of about 20.8%,26.3%,and 36.14%,respectively,when compared to a flat plate at a solar irradiation of 900 W/m2.展开更多
Due to their simple structure,crooked plates are widely processed into energy absorption structures.There are obvious differences in the final deformation of crooked plates with different materials and dynamic conditi...Due to their simple structure,crooked plates are widely processed into energy absorption structures.There are obvious differences in the final deformation of crooked plates with different materials and dynamic conditions under the impact of constant-input kinetic energy.To better understand this phenomenon,we solved the Zhang-Yu equation with Maple software,obtained the law of generalized coordinates(rotation angle)of the energy absorber changing with time,and compared the energy absorption capacity of a crooked plate energy absorber under different parameters.To better understand how the motion of the energy absorber is affected by the change of parameters,we calculated the phase diagram of the energy absorber dynamics.After many numerical simulations,we found that the four-crooked plate energy absorber should have a mass-sensitive structure.We established the finite element model of dynamic buckling of mild steel and 6061-T6 aluminum alloy,and compared it with the Calladine-English dynamic experiment and Zhang-Yu rigid viscoplastic model.The results show that:(1)the Zhang-Yu rigid viscoplastic model has more guiding significance for mild steel(strain rate-sensitive material),and has greater error for 6061-T6 aluminum alloy(strain rate-insensitive material),and the prediction error further increases with the initial angle;and(2)by modifying the equivalent plastic length A of a plastic hinge according to the finite element model,the prediction accuracy of the Zhang-Yu rigid viscoplastic model can be improved.Our research results certain guiding significance for the design and manufacture of energy-absorbing structures of crooked plates.展开更多
The interaction of two coherent counter propagating TE （transverse-electric） and TM （transverse-magnetic） electromagnetic waves with different initial phases in the absorbing plate placed in the regular ideal wave...The interaction of two coherent counter propagating TE （transverse-electric） and TM （transverse-magnetic） electromagnetic waves with different initial phases in the absorbing plate placed in the regular ideal waveguide is considered. The losses of energy of TE and TM waves in the absorbing plate are calculated. Some features of tunnel interference in the absorbing plate in the waveguide are revealed. It is shown that the losses of energy strongly depend on the various parameters describing the interaction of the counter propagating waves. Definitely choosing the parameters we can control the electromagnetic processes in this case.展开更多
文摘Solar energy,a renewable resource,can be harnessed instead of fossil fuels to generate power and heat.One effective method for converting solar energy into heat is through a solar air heating(SAH)system.The theoretical investigation focused on the thermal performance of various V-groove angles on a corrugated absorber plate.The researchers maintained the exterior dimensions and constraints of the absorber plate while increasing its surface area by using a corrugated absorber surface.For the simulation,three different V-groove angles were employed:45°,30°,and 15°.The temperature and air flow rate into the system had been set at 30℃ and 0.15 m/s,respectively four various solar radiation intensities have been examined for each of the variables.The governing equations associated with the standard design,including the turbulent kinetic energy(k)and dissipation rates model(ε),were solved using the ANSYS 2020 R2 program.The results indicated that Utilizing corrugated absorber plates resulted in a rise in the Nusselt number.,surpassing the performance of flat plate absorbers.Among the different configurations,the V-grooved 45°plate demonstrated the best results under the same conditions.Furthermore,it was observed that the efficiency values improved with increasing solar irradiance.The investigation also showed that the employing of V-grooved 45°,V-grooved 30°,and V-grooved 15°absorbers led to efficiency improvements of about 20.8%,26.3%,and 36.14%,respectively,when compared to a flat plate at a solar irradiation of 900 W/m2.
文摘Due to their simple structure,crooked plates are widely processed into energy absorption structures.There are obvious differences in the final deformation of crooked plates with different materials and dynamic conditions under the impact of constant-input kinetic energy.To better understand this phenomenon,we solved the Zhang-Yu equation with Maple software,obtained the law of generalized coordinates(rotation angle)of the energy absorber changing with time,and compared the energy absorption capacity of a crooked plate energy absorber under different parameters.To better understand how the motion of the energy absorber is affected by the change of parameters,we calculated the phase diagram of the energy absorber dynamics.After many numerical simulations,we found that the four-crooked plate energy absorber should have a mass-sensitive structure.We established the finite element model of dynamic buckling of mild steel and 6061-T6 aluminum alloy,and compared it with the Calladine-English dynamic experiment and Zhang-Yu rigid viscoplastic model.The results show that:(1)the Zhang-Yu rigid viscoplastic model has more guiding significance for mild steel(strain rate-sensitive material),and has greater error for 6061-T6 aluminum alloy(strain rate-insensitive material),and the prediction error further increases with the initial angle;and(2)by modifying the equivalent plastic length A of a plastic hinge according to the finite element model,the prediction accuracy of the Zhang-Yu rigid viscoplastic model can be improved.Our research results certain guiding significance for the design and manufacture of energy-absorbing structures of crooked plates.
文摘The interaction of two coherent counter propagating TE （transverse-electric） and TM （transverse-magnetic） electromagnetic waves with different initial phases in the absorbing plate placed in the regular ideal waveguide is considered. The losses of energy of TE and TM waves in the absorbing plate are calculated. Some features of tunnel interference in the absorbing plate in the waveguide are revealed. It is shown that the losses of energy strongly depend on the various parameters describing the interaction of the counter propagating waves. Definitely choosing the parameters we can control the electromagnetic processes in this case.
