Alberto Verga

Politecnico di Milano | Polimi · Department of Aerospace Engineering

The attractive features of hybrid rocket propulsion could be fully exploited, and the inherent drawbacks overcome thanks to the armored grain approach. The armored grain, a heterogeneous paraffin-based fuel grain consisting of a paraffin matrix embedding a 3D printed polymeric gyroid-like reinforcement, is studied inspecting the mechanical properti...

View Video Presentation: https://doi.org/10.2514/6.2021-3519.vid The combustion behavior of paraffin-based blends is investigated by a lab-scale vortex flow pancake motor (VFP). A complete pre-burning characterization for different paraffin-based fuel formulations is performed. The tested compositions are based on a micro-crystalline paraffin wax (...

View Video Presentation: https://doi.org/10.2514/6.2021-3502.vid Although affordable and fast burning, paraffin waxes are rarely exploited as fuels in real flying systems because of their poor mechanical properties. To date, the identification of the paraffin-based formulations offering both high ballistic performance and structural integrity is st...

Paraffin-based hybrid rocket engines could accomplish the current demanding requirements for mass access to space, i.e., low environmental impact, cost reduction, and reliability maximization. However, the poor mechanical properties of paraffin waxes frustrate the high ballistic performance and hamper the exploitation of this technology. To date, h...

In the framework of a cooperation agreement between SPLab of Politecnico di Milano and ICMATE-CNR (National Research Council), two different configurations of a rectangular geometry small scale model engine fuelled with gaseous hydrogen were tested at Mach 5.4 in a high enthalpy pulse facility. A dual-mode scramjet setup was first studied and the m...

This paper studies the aging behavior of four nano-sized aluminum powders, stored under different conditions in terms of temperature and relative humidity. The nominal particle size of the powders is in the range 40 −200 nm. The particle size distribution of the fresh powders was assessed, as well as the particles morphology and structure, the comp...

Low regression rate is nowadays the main issue of hybrid rocket engines (HREs). The exploitation of paraffin-based fuels could be the answer to this problem. In the present study, ballistic behavior of HTPB and paraffin-based fuel blends are studied and compared with the one of the armored grains, new generation of fuels featuring 3D-printed cellul...

Nano-sized Al (nAl) features high reactivity implying possible issues related to its aging during storage. In this work, the aging behavior of micron-sized Al and nAl is investigated considering different relative humidity (RH) conditions (10% and 80%) at the temperature of 333 K. The marked aging sensitivity of nAl (100 nm) is testified by an almo...

Nano-sized Al (nAl) is an attractive candidate for the performance enhancement of current solid propellant formulations, and its characteristics are relevant for the development of innovative solid fuels for hybrid rocket propulsion. Nano-sized Al powders feature a higher reactivity than their micron-sized counterpart. While desirable for effective...

Nano-sized Al (nAl) features high reactivity that, while desirable for effective energy conversion during the combustion, yields possible issues related to its storage. This paper investigates the ageing behavior of nAl under different relative humidity conditions (RH, from 80% to 10%) at the temperature of 333 K. Fresh and aged powders are charact...