Experimental and numerical study of effecting core configurations on the static and dynamic behavior of honeycomb plate with aluminum material

The sandwich panel incorporated a honeycomb core,a widely utilized composite structure recognized as a fundamental classification of composite materials.Comprised a core resembling a honeycomb,possessing thickness and softness,and is flank by rigid face sheets that sandwich various shapes and materials.This paper presents an examination of the static and dynamic analysis of lightweight plates made of aluminum honeycomb sandwich composites.Honeycomb sandwich plate samples are 300 mm long,and 300 mm wide,the heights of the core have been varied at four values ranging from 10 to 25 mm.The honeycomb core is manufactured from Aluminum material by using a novel technique namely resistance spot welding(RSW)instead of using adhesive material,which is often used when an industrial flaw is detected.Numerical optimization based on response surface methodology(RSM)and design of experiment software(DOE)was used to verify the current work.A theoretical examination of the crashworthiness behavior(maximum bending load,maximum deflection)and vibration attributes(natural frequency,damping ratio,transient temporal response)of honeycomb sandwich panels with different design parameters was also carried out.In addition,the finite element method-based ANSYS software was used to confirm the theoretical conclusions.The findings of the present work showed that the relationship between the natural frequency,core height,and cell size is direct.In contrast,the relationship between the natural frequency and the thickness of the cell wall is inverse.Conversely,the damping ratio is inversely proportional to the core height and cell size but directly proportional to the thickness of the cell wall.The study indicates that altering the core height within 10-25 mm leads to a significant increase of 82%in the natural frequency and a notable decrease of 49%in the damping ratio.These findings are based on a specific cell size value of 0.01 m and a cell wall thickness of 0.001 m.Also,the results indicate that for a given set of cell wall thickness and size values,an increase in core height from(0.01-0.025)m,leads to a reduction of the percentage of maximum response approX imately 76%.Conversely,the increasing thickness of the wall of cell wall,ranging 0.3-0.7 mm with a constant core height equal to 0.015 m,resulted in a de crease of maximum transient response by 7.8%.

Experimental and numerical analyses of nitrogen oxides formation in a high ammonia‑low hydrogen blend using a tangential swirl burner

Ammonia has been considered as a novel fuel for decarbonization purposes.However,emissions from combustion systems are still posing a problem.Therefore,experimental and numerical simulations have been conducted to study the concentration of exhaust emissions(Nitric oxide“NO”,Nitrous oxide“N_(2)O”)from burning the ammonia/hydrogen(NH_(3)/H_(2))blend 85/15(vol%).The effects were measured at various thermal powers ranging 10 to 20 kW and with different Reynolds numbers from 20,000—40,000.The experimental points were numerically investigated in the Ansys CHEMKIN-Pro environment employing seven chemical kinetic mechanisms taken from the literature.All experiments have been undertaken at standard atmospheric conditions.The experimental results showed that both NO and N_(2)O gradually increased when the Reynolds number increased from 20,000 to 40,000.Along with that,the concentration of NO emissions at the exhaust reported minimum level when the Re=20,000 due to lower reactivity radical formation,all that led to a deterioration of the flame characteristics.Also,the integrated radical intensities of NO*,OH*,NH*,and NH_(2)*demonstrate an increasing trend as Re increased from 20,000 to 40,000.In terms of thermal power,N_(2)O suffered an abrupt decrease when the thermal power increased up to 15 kW,while the opposite occurs for NO.In addition,the radicals intensity of OH*,NH*and NH_(2)*figures show an increase in their concentration when the thermal power increased up to 15 kW then decreased with increasing thermal intensity to reach 20 kW,reflecting into increased NO productions and decreased N_(2)O levels.The numerical analysis showed that Stagni,Bertolino,and Bowen Mei were the most accurate mechanisms as these give a good prediction for NO and N_(2)O.The study also showed that the chemical reaction(HNO+O_(2)←→NO+HO_(2))is the main source of NO formation.While the chemical reaction(NH+NO←→N_(2)O+H)is responsible for the formation of N_(2)O by consuming NO and when there will be abundance in NH radicals.Finally,dealing with a blended fuel of high ammonia concentration encourages ammonia chemistry to become more dominant in the flame.It decreases the flame temperature,hence lowering heat loss between the flame and the surrounding.