Energy-Efficient Retrofit Measures to Achieve Nearly Zero Energy Buildings

Considering the 2021 IPCC report that justly attributes our deteriorating climatic condition to human doing, the need to develop nearly zero energy building (nZEB) practices is gaining urgency. However, rather than the typical focus on developing greenfield net-zero initiatives, retrofitting underperforming buildings could create significant scale climate positive impacts faster. The chapter accordingly discusses energy-efficient retrofitting methods under three categorical sectors—visual comfort (daylight-based zoning, shadings); thermal comfort and ventilation (solar radiation-based zoning, central atrium plus interior openings, insulation, and window replacement); energy consumption (efficient lighting system, and controllers, material and HVAC system optimization, PV panels as the renewable energy source). This chapter further substantiates these theoretical underpinnings with an implemented design scheme—an educational building within a cold semiarid climatic condition—to showcase the on-ground impact of these retrofitting strategies in reducing the energy used for heating and cooling and lighting purposes.

Design and Numerical Analysis of Electric Vehicle Li-Ion Battery Protections Using Lattice Structure Undergoing Ground Impact

Improvement in electric vehicle technology requires the lithium-ion battery system’s safe operations, protecting battery fire damage potential from road debris impact. In this research a design of sandwich panel construction with a lattice structure core is evaluated as the battery protection system. Additive manufacturing technology advancements have paved the way for lattice structure development. The sandwich protective structure designs are evaluated computationally using a non-linear dynamic finite element analysis for various geometry and material parameters. The lattice structure’s optimum shape was obtained based on the highest Specific Energy Absorption (SEA) parameter developed using the ANOVA and Taguchi robust design method. It is found that the octet-cross lattice structure with 40% relative density provided the best performance in terms of absorbing impact energy. Furthermore, the sandwich panel construction with two layers of lattice structure core performed very well in protecting the lithium-ion NCA battery in the ground impact loading conditions, which the impactor velocity is 42 m/s, representing vehicle velocity in highway, and weigh 0.77 kg. The battery shortening met the safety threshold of less than 3 mm deformation.

Structural Lattice Topology and Material Optimization for Battery Protection in Electric Vehicles Subjected to Ground Impact Using Artificial Neural Networks and Genetic Algorithms

A critical external interference that often appears to pose a safety issue in rechargeable energy storage systems (RESS) for electric vehicles (EV) is ground impact due to stone impingement. This study aims to propose the new concept of the sandwich for structural battery protection using a lattice structure configuration for electric vehicle applications. The protective geometry consists of two layers of a twisted-octet lattice structure. The appropriate lattice structure was selected through topology and material optimization using an artificial neural network (ANN), genetic algorithms (GA), and multi-objective optimization with technique for order of preference by similarity to ideal solution (TOPSIS) methods. The optimization variables are the lattice structure relative density, ρ¯, angle, θ, and strength of the materials, σy. Numerical simulations were used to model the dynamic impact loading on the structures due to a conical stone mass of 0.77 kg traveling at 162 km/h. The two-layer lattice structure configuration appears to be suitable for the purposes of RESS protection. The optimum configuration for battery protection is a lattice structure with an angle of 66°, relative density of 0.8, and yield strength of 41 MPa. This optimum configuration can satisfy the safety threshold of battery-shortening deformation. Therefore, the proposed lattice structure configuration can potentially be implemented for electric vehicle applications to protect the battery from ground impact.

Kinematic and dynamic aspects of chimpanzee knuckle walking - finger flexors likely do not buffer ground impact forces

Chimpanzees are knuckle-walkers, with forelimbs contacting the ground by the dorsum of the finger's middle phalanges. As these muscular apes are given to high velocity motions, the question arises how the ground reaction forces are buffered so that no damage ensues in the load bearing fingers. In literature, it was hypothesized that the finger flexors help buffer impacts because in knuckle stance the metacarpophalangeal joints (MCPJ) are strongly hyperextended, which would elongate the finger flexors. This stretching of the finger flexor muscle-tendon units would absorb impact energy. However, EMG studies did not report significant finger flexor activity in knuckle walking. While these data by themselves question the finger flexor impact buffering hypothesis, the present study aimed to critically investigate the hypothesis from a biomechanical point of view. Therefore, various aspects of knuckle walking were modeled and the finger flexor tendon displacements in the load bearing fingers were measured in a chimpanzee cadaver hand, of which also an MRI was taken in knuckle stance. The biomechanics do not support the finger flexor impact buffering hypothesis. In knuckle walking, the finger flexors are not elongated to lengths where passive strain forces would become important. Impact buffering by large flexion moments at the MCP joints from active finger flexors would result in impacts at the knuckles themselves, which is dysfunctional for various biomechanical reasons and does not occur in real knuckle walking. In conclusion, the current biomechanical analysis in accumulation of previous EMG findings suggests finger flexors play no role in impact buffering in knuckle walking.

Observing the impossible – in situ observations of hail trajectories using the HailSonde

<p>From the early stages of hailstone growth to the ground-impact finale, a trajectory is taken by each hailstone through the parent hailstorm. Larger hailstones form as their trajectory takes them into regions of the storm that are more favorable for growth, while others may miss out entirely. Simulation-based studies have shown that interactions between the hailstone fall speed, aerodynamics, storm winds (which continue to change along the trajectory and with new growth) can take hailstones on a myriad of different trajectories. Despite improvements in radar technology over the last 20 years, operational hail analysis techniques have changed little, and do not consider trajectories, leaving a high degree of uncertainty when estimating ground impact.</p> <p>Case studies have demonstrated that trajectory information provides significant improvements to hail impact mapping and nowcasting services, but the lack of robust<br />observational datasets to leverage new radar technology and verify trajectories prevents the transition of this new science into operations. The follow proposal presents an innovative approach to measuring trajectories within a hailstorm using hailstone-shaped probes called “HailSondes”. Recent advances in low-energy telemetry, battery technology and electronics miniaturization are combined to make this new sensor possible, which, until recently, was the realm of fantasy for meteorologists (e.g., the 1996 Hollywood classic “Twister” imagined a similar sensors for observing tornadoes). The design challenges, simulations, prototype development and deployment of HailSondes are discussed.</p> <p>HailSonde measurements will provide critical validation for the practical application radarderived trajectories for hailstorm analysis and nowcasting, supporting the transition to future hail services and benefiting a wide range of sectors from aviation, risk management, transport and public safety. This transition from science fiction into real science signifies extraordinary potential for further remote micro-sensor applications in the future. </p>

Energy Absorption in Actual Tractor Rollovers with Different Tire Configurations

In order to better understand the complexities of modern tractor rollover, this paper investigates the energy absorbed by a Roll-Over Protective Structure (ROPS) cab during controlled lateral rollover testing carried out on a modern narrow-track tractor with a silent-block suspended ROPS cab. To investigate how different tractor set-ups may influence ROPS and energy partitioning, tests were conducted with two different wheel configurations, wide (equivalent to normal ‘open field’ operation) and narrow (equivalent to ‘orchard/vineyard’ operation), and refer to both the width of the tires and the corresponding track. Dynamic load cells and displacement transducers located at the ROPS-ground impact points provided a direct measurement of the energy absorbed by the ROPS cab frame. A trilateration method was developed and mounted onboard to measure load cell trajectory with respect to the cab floor in real-time. The associated video record of each rollover event provided further information and opportunity to explain the acquired data. The narrow tire configuration consistently subjected the ROPS cab frame to more energy than the wide tire arrangement. To better evaluate the influence of the ROPS cab silent-blocks in lateral rollover, static and dynamic tests were performed. The results confirm that tires influence the energy partition significantly and that further understanding of silent-blocks’ dynamic performance is warranted.

Dissipation of Energy in Sandwich-Structured Equestrian Helmet – Numerical Analysis Under Overload Conditions

Protection of the head structures is a requirement in many sports where a person is exposed to injuries that threaten life or health. In horse riding accidents occur often, resulting in serious head injuries. The analysis of the available literature shows that the helmets used now protect human head structures in a small percentage. The aim of the research was to analyze the degree of protection of the human head using available helmet structure and a new solution for the Energy absorbing layer in helmet that absorbs Energy from impacts. The research was divided into two stages. During the first one, a simulation was performer under dynamic conditions simulating the rider’s fall and the contact of the head with ground (impact from the side). In the second stage, three structures of the absorbing layers were developed, i.e. honeycomb, auxetic, mixed with three three wall thicknesses (1 mm, 2 mm and 3 mm respectively) and two materials were used: the currently used EPS and the aluminium alloy used in the motorcycle helmet.