Low Ground Clearance Research Articles

Study on Tractive System and Power Conveyance of EV Go-Kart

Abstract: This paper gives an overview on a cognizant strategy while selecting the major components of tractive system and power conveyance of Ev go-kart. This study was compiled according to the rules specified in the 2023-2024 GKDC. Go-Kart is a racing vehicle having very low ground clearance and can be worked on only flat racing circuits. The vehicle is iterative and is based on various engineering and reverse engineering processes depending upon the availability, cost and other such factors. All the parameters like Reliability, safety, Cost, Performance, aesthetics, ergonomics, Standard dimensions & material were also taken into consideration at the same time. We have also taken into account the battery management system, motors and other electrical management systems along with a brief description about their working and specifications. Through detailed analysis of the tractive system components such as motors, controllers, batteries, and drivetrain configurations, this research seeks to identify key parameters influencing the overall performance and acceleration characteristics of electric gokarts. Furthermore, the project evaluates the impact of various factors including motor selection, battery technology, and drivetrain layouts on the overall efficiency and dynamic response of electric go-karts. The findings of this study contribute valuable insights for enhancing the design and performance of electric go-karts, thus advancing the development of sustainable and high-performance recreational and competitive electric go-karts

Factor that Contributes to the Ramp Design and the Effective Gradient for Ramp at Entrance Carporch Area for Housing Sector in Double-Storey House to Accommodate Low-Clearance Vehicles

The main aim of this study is to propose the effective gradient for different dimensions between ground clearances vehicles for ramp design in car porch areas for the housing sector. There are many guidelines and standards have been established, such as Building (Federal Territory of Kuala Lumpur) By-Laws 1985, Selangor Uniform Building By-Laws 1986, Guidelines for Car Parking ad Internal Traffic Circulation (Wilayah Persekutuan Kuala Lumpur 2018), Malaysian Standard 2426 1 2011, and Neufert Architect’s Data (Fourth Edition) as references to the consultants. However, each guideline shows only minimum guidelines and is not specific for each type of vehicle, especially vehicles which have lowered skirtings, such as sports cars or hummer vehicles. Hence, the aim of this research is to propose the effective gradient for different dimensions between ground clearances vehicles for ramp design in car porch areas for the housing sector and to determine the issues of ramp design at car porch in housing and residential area. To propose the effective gradient, the research will focused on the factor that contributes to the ramp design for accommodating low-ground clearances vehicles on high profile at the car porch area. In other words, to achieve this aim, an interview session has been held with the professional parties with architects, engineers in the engineering department at Majlis Bandaraya Seremban, DBKL, Majlis Bandaraya Melaka, Majlis Bandaraya Johor Bahru, Jabatan Kerja Raya (JKR) and consultant firms. The data that been collected during the interview session is based on the four aspects that are background of interview, existing guidelines and standards of ramp design, impact of improper design to residents and proposed the specific high ramp design criteria in a different situation to accommodate low-clearance vehicles. The researcher analyzed the data by grounded theory and color coding based on the respondents’ feedback. In short, after the researcher completes all the data collection, the researcher makes a conclusion and summary to propose the maximum gradient for different dimensions between the different dimensions of ground clearances. These data can be used to estimate the suitable degree and percent for different categories of ground clearances which is useful for current development and current technology circulation.

Proactive Body Joint Adaptation for Energy-Efficient Locomotion of Bio-Inspired Multi-Segmented Robots

Typically, control strategies for legged robots have been developed to adapt their leg movements to deal with complex terrain. When the legs are extended in search of ground contact to support the robot body, this can result in the center of gravity (CoG) being raised higher from the ground and can lead to unstable locomotion if it deviates from the support polygon. An alternative approach is body adaptation, inspired by millipede/centipede locomotion behavior, which can result in low ground clearance and stable locomotion. In this study, we propose novel proactive neural control with online unsupervised learning, allowing multi-segmented, legged robots to proactively adapt their body to follow the surface contour and maintain efficient ground contact. Our approach requires neither kinematics nor environmental models. It relies solely on proprioceptive sensory feedback and short-term memory, enabling the robots to deal with complex 3D terrains. In comparison to traditional reflex-based control, our approach results in smoother and more energy-efficient robot locomotion on terrains with concave and convex curves or slopes of varying degrees in both simulation and real-world implementation.

A study on structural behaviour and vibrational characteristics of a go-kart chassis

A go-kart is a four-wheel drive that lacks a suspension system and differential unit due to the very low ground clearance usually employed for Formula E or Formula 1 racing. Due to the absence of a suspension system, the chassis of the go-kart should be rigid and strong enough to withstand the impact loads, as well as other support equipment. The present research focused on the design, material selection, and structural and vibrational analysis on the go-kart chassis. For this, the chassis is designed with suitable dimensions and materials. In this, the chassis is modelled by using CATIA V5 software and performed static structural and vibrational analysis by using Finite Element Analysis (FEA) ANSYS software. The chassis was designed with Circular pipes with a diameter of about 26.4 mm with a 4 mm pipe thickness made of AISI 1018, AISI 1026, AISI 4130, and structural steel were chosen due to their superior mechanical properties to perform the finite element analysis to find the total deflection, equivalent stress, factor of safety and first six mode shapes of the chassis configuration.

Design of Electric- Go Kart

Abstract: The aim of our project is the development of an electric GO kart vehicle to reduce emission of hazardous pollutant gases and to design and develop a vehicle which works efficiently on electric power. E-Kart is a racing vehicle having very low ground clearance and can be worked on only flat racing circuits.This paper concentrates on explaining the engineering behind the design of a safe, rigid and torsional free frame, well-mounted power train along with the braking and steering system. We approached our design by considering all possible alternatives for a system and modelling them in SOLIDWORKS.

Mechanism Operation for Changing the Rear Axle Clearance of a Universal Row-crop Tractor

The authors noted the disadvantages of the 3-wheel universal row-crop tractor. To eliminate them, LLC Design and Technological Center for Agricultural Engineering developed a 4-wheel universal row-crop tractor with variable ground clearance.(Research purpose) To determine the pressure change in the hydraulic system and the transfer time of the rear axle from one type of clearance to another.(Materials and methods) The authors showed that the rear axle clearance could be changed using a special mechanism - with minimal labor costs, without the use of lifting equipment and assembly and dismantling works. They explained that the mechanism was driven by a working hydraulic cylinder. The experiments were carried out on a prototype tractor with adjustable ground clearance, equipped with a separate-aggregate hinged system at an engine speed of 1200-2000 rpm (revolutions per minute). M10G2K oil was used in the hydraulic system, heating it to 65 degrees Celsius (at an ambient temperature of 33-35 degrees Celsius).(Results and discussion) The hydraulic system consisted of an NSh-32 hydraulic pump, a P80 hydraulic valve, two Ts50-200 working hydraulic cylinders, a double-acting hydraulic lock, a hydraulic tank, filters, hoses and high pressure pipes. At the inlet and outlet channels of the working hydraulic cylinders, which activated the mechanism for changing the rear axle clearance, hydraulic locks were installed, and diaphragm pressure sensors model SS302 from Sendor Sensor with a measurement range from 0 to 40 megapascals were placed along the hydraulic line connecting the hydraulic locks with the hydraulic valve.(Conclusions) The authors determined that the time for transferring the rear axle from low clearance to high was 2.2-4.4 seconds, and the pressure in the hydraulic system was 3.8-16.4 megapascals at an engine speed of 1300-2000 rpm. It was found that when transferring from high to low ground clearance, these indicators amounted to 1.0-1.4 seconds and 0.99-9.90 megapascals.

Behavior of the square-back Ahmed body global modes at low ground clearance

A study of the evolution of the wake flow of a square-back Ahmed body is presented. Various ground clearance configurations around the critical case associated with the onset of the lateral bistability are investigated. The oscillation modes vary between stable and bistable states, the corresponding Strouhal numbers for the horizontal (respectively, vertical) evolve from 0.16 (respectively, 0.27) to 0.13 (respectively, 0.18).

CFD analysis of the performance of different airfoils in ground effect

Ground effect is a phenomenon caused by the presence of a fixed boundary layer below the wing when it moves close to a fixed surface. This results in an effective increase in lift to drag ratio of the airfoil. In this paper, the performance of three airfoils used in general aviation is analysed in ground effect using ANSYS FLUENT at different operating conditions namely, the angle of attack and the height above the fixed surface. The main objectives are to are evaluate the performance of these airfoils in ground effect at different ground clearances and angles of attack and find the most suitable airfoil which can be used to exploit the advantages of ground effect. It was found that all the airfoils experienced an increase in lift and decrease in drag as distance from the ground reduced thus validating ground effect. The aerodynamic efficiency increases, reaches a maximum, and then decreased as the angle of attack increased due to the onset of flow separation at the top surface of the airfoil. It was also noted that the symmetric airfoil experienced negative lift at very low ground clearances which was attributed to the formation of a venturi effect between the airfoil and ground

Comparison of Bifacial Solar Irradiance Model Predictions With Field Validation

Models predicting rear irradiance for bifacial systems are critical to establish accurate estimates of energy yield. Here, we compare five published bifacial irradiance models, varying clearance, row spacing, tilt, and albedo to measure the sensitivity to these parameters. Bifacial energy gains (BGE) as high as 20% are predicted for some configurations. Model agreement is generally good for low ground clearance (clearance heights lower than 0.75 times the collector width), but at higher clearances, finite system size and edge effects become a significant factor in simulations, stretching assumptions of infinite system extent made in some models. In addition, rear irradiance uniformity is improved at high ground clearance, as expected. A test-bed construction and results are described for comparison between modeled and measured data in Golden, CO, USA. The investigations indicate that model agreement for BGE calculation is better than 2% (absolute) when compared with measured results, depending on the system configuration.

Application of Terrestrial Laser Scanner to Evaluate the Influence of Root Collar Geometry on Stump Height after Mechanized Forest Operations

The height of tree stumps following mechanized forest operations can be influenced by machine-, tree-, terrain-, and operator-related characteristics. High stumps may pose different economic and technical disadvantages. Aside from a reduction in product recovery (often associated with sawlog potential), leaving high stumps can complicate future entries if smaller equipment with low ground clearance is used, particularly in the case where new machine operating trails are required. The objective of this exploratory study was to examine if correlations existed between the height of tree stumps following mechanized harvesting and the shape of the above-ground root collar, stump diameter, and distance to the machine operating trail. In total, 202 sample stumps of Norway spruce (Picea abies (L.) Karst.) and the surrounding terrain were scanned with a terrestrial laser scanner. The collected data was processed into a 3D-model and then analyzed. Stump height was compared with different characteristics such as stump diameter at the cut surface, distance to the machine operating trail, number of visible root flares per stump, and the root collar. The number of root flares per stump had a positive influence on stump diameter and height, showing a general trend of increasing diameter and height with the increasing number of root flares. Root angles also had an influence on the stump diameter. The diameter of a stump and the shape of the root collar at the cut surface together had a significant effect on stump height and the model reported explained half of the variation of stump heights. Taken together, these findings suggest that other factors than the ones studied can also contribute in influencing stump height during mechanized harvesting operations. Further investigations, including pre- and post-harvest scans of trees selected for removal, are warranted.

A novel technique and detailed analysis of cars in Indian roads to adopt low ground clearance

ABSTRACT As the front wheels of a car descend along the slope of a bump, the vehicle comes down due to inertia. This motion is dampened by the suspension system. The Indian cars with low ground clearance when moving over bumps tend to have their under chassis brushed by the road surface which is mostly harmless. But if the bumps are too steep, the under chassis takes a hit .The result is damage to the critical parts of the vehicle. So our idea is to develop a system that will detect the presence of elements (bumps, speed breakers, stones, etc.,) in the course of the vehicle that could possibly cause serious damage to the vehicle’s under chassis and other critical parts. The system we propose aims to identify the presence of such unsafe obstacles. The system adopted for Indian cars will merely harden the suspension using MR damper to provide a small lift sufficient enough to the system. We aim to identify the presence of such unsafe obstacles. The system adopted for Indian cars will merely harden the suspension using MR damper to provide a small lift sufficient enough to get through the bumps.

Numerical analysis of the effect of the change in the ride height on the aerodynamic front wing–wheel interactions of a racing car

An investigation into the influence of the ground clearance on the aerodynamic interactions between the inverted front wing and the wheel of a racing car was conducted using computational fluid dynamics. Height-to-chord ratios h/ c from 0.075 to 0.27 were assessed for a single-element wing with a fixed angle of 4° and for two wing spans, one of which completely overlapped the wheel and the other which had its endplate coincident with the inside face of the wheel. With a narrower span, a lower peak downforce was achieved at a higher ground clearance owing to changes in the lower endplate vortex strength whereas, with a wider span, no downforce loss was observed, with decreasing clearance for those tested. This contrasted distinctly with the performance of the wing in isolation. The wheel lift was scarcely affected with decreasing wing ground clearance for the narrower span but decreased significantly for the wide-span wing at low ground clearances. The vortex paths changed considerably with the ground clearance, with a strong coupling to the wing span; a state in which the main vortex was destroyed in the contact patch of the wheel was identified.

Investigation of full and partial ground effects on a flapping foil hovering above a finite-sized platform

The full and partial ground effects on the lift generation of a flapping airfoil in normal hovering mode are investigated numerically using the discrete vortex method in two dimensions. To achieve full ground effect, the airfoil of chord c is made to hover above the center of a finite-sized platform of length 10c. We have observed the force-enhancement, force-reduction, and force-recovery regimes at low, medium, and high ground clearances in line with the existing literature. This paper puts special focus on partial ground effect when the airfoil is hovering near the edge of the platform. Lift-modifying mechanisms not previously observed under full ground effect have been discovered. When stroke reversal occurs near the edge of the platform, a relatively stationary strong vortex may form above the platform edge. This strong vortex can either increase or decrease the instantaneous lift force on the airfoil depending on the position of the airfoil relative to the platform edge. Also, the platform edge may lead to the formation of an additional vortex pair which increases the instantaneous lift force as the airfoil sweeps past the edge under suitable conditions. Lastly, the platform edge can lead to the formation of a reverse von Kármán vortex street that extends well below the stroke plane under suitable geometric arrangements.

Aerodynamics of a Pitching and Heaving Airfoil in Ground Effect

The aerodynamics of an inverted airfoil close to a moving ground oscillating periodically in pure pitching motion and in combined pitching–heaving motion has been studied numerically. The main effect of the ground in pure pitching is to increase separation on the suction side, leading to larger hysteresis. At low frequencies, the airfoil under pitching motion can stall if the flow remains separated for a large part of the cycle. This type of stall is characteristically different from dynamic stall in freestream. Regarding the combined pitching and heaving motion, the pitch mode controls the flow at low frequencies, whereas the heave mode prevails at high frequencies. The interaction between both modes of motion is determined by the phase shift between them, and the modes can interact positively or negatively. The introduction of heaving can help improve the stall characteristics of an isolated pitching motion when flapping at low ground clearances.

Application of Light Detection and Ranging Technology to Assess Safe Passage of Low-Ground-Clearance Vehicles at Highway–Rail Grade Crossings

The objectives of this research were to test and validate the feasibility of assessing humped highway–rail crossings for safe passage of vehicles with low ground clearance using lidar data. Collected using an airborne platform, lidar data provide georeferenced spatial information about the shape and surface characteristics of Earth. The suitability of humped highway–rail crossings for use by vehicles with low ground clearance and a long wheelbase is a concern because of the possibility of vehicles getting lodged on rail tracks. While such vehicles usually travel on designated routes, emergencies or highway closures may result in these vehicles traveling on undesignated highways with humped grade crossings. Lidar data and line-of-sight analysis in a geographic information system (GIS) were used to identify potentially problematic grade crossings for certain types of low-ground-clearance vehicles with a long wheelbase. Results of the GIS analysis were validated in the field at actual grade crossings with survey equipment. The main conclusion was that lidar data could be successfully used for identification of highway–rail crossing vehicle hang-up issues.

Experimental Investigation of a Wing-in-Ground Effect Craft

The aerodynamic characteristics of the wing-in-ground effect (WIG) craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM) wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future.

Implications of compressibility effects for Reynolds-scaled testing of an inverted wing in ground effect

The influence of compressibility around an isolated inverted wing at a fixed Reynolds number was examined as relevant to the issue of wind tunnel scaling effects. Three-dimensional simulations were conducted for low ground clearances, at: full scale and a Mach number of 0.088, at 50% scale at Mach 0.176, and at 25% scale at Mach 0.352. As the scale was reduced, the increasing peak local Mach number between the wing and the ground resulted in a higher propensity of the flow to separate towards the trailing edge, and for incompressible or full-scale CFD to underestimate the lift and drag coefficients by an ever-increasing margin. The lower vortex path was less affected. The results suggest that compressible CFD of a scale experiment ought to be conducted at the same Reynolds number and Mach number as the tunnel test for the best possible correlation at free-stream Mach numbers beyond 0.15.

SUITABILITY OF EXISTING TRAFFIC CALMING MEASURES FOR USE ON SOME HIGHWAYS IN EGYPT

ABSTRACTThe most common traffic calming measures on roadway network in Egypt are speed humps and cat-eye reflectors; the second one was investigated in previous study and found ineffective as traffic calming device on highways. This research examines the suitability of the existing speed humps on a major highway in Egypt for use, Cairo-Aswan agricultural highway was selected for this study, it is two-way two-lane highway, 140 km of it passing through Minia governorate and the posted speed limit is 90 km/h reduced to 60 km/h at dwelling zones. More than 150 speed humps exist on this highway in Minia region, located at intersections and entrance of towns and villages existing around that highway. Field measurements of speed, speed humps geometry, distance between humps, and in-depth interviews with different driver groups were used to assess the suitability of existing speed humps for use. The results show that most of speed humps are too high and some of them reach 25 cm height, low ground clearance vehicle' drivers complain that they cannot traverse without maneuvering speed humps, all drivers complain from rarity of signage, painting, and precautions which indicates the presence of speed humps, that led to traffic safety problems. Due to speed humps geometry, density of speed humps, and volume of traffic, much of delay and fuel consumption as well as damage of vehicles parts happen. The findings indicate that existing traffic calming measures are unsuitable for use in this class of highway.

Three-Dimensional Investigation of Smart Flap Aerodynamics for a WIG Vehicle

Department of Mechanical Engineering, Ferdowsi University of Mashhad, Iran (Received December 9th, 2010) Aerodynamic characteristics of a wing with a smart flap under the ground effect are studied through the integration of computational fluid dynamics. A parametric bending profile of a smart flap is designed considering different types of beams. Here, a cantilever beam with uniformly varying load with roller support at the free end is considered. The shape of the smart flap is fixed and its advantage comes from its smooth connection to the main wing. In this research, a pressure-based implicit procedure is used to solve Navier-Stokes equations. A non-orthogonal mesh with collocated finite volume formulation is utilized to simulate flow around the wing under the ground effect. First, the method is validated against experimental data. Then, the algorithm is applied for turbulent aerodynamic flows around a wing with smart and conventional flaps for different flap angles and ground clearance. The results of the two wings are compared. It is found that the pressure coefficient distribution for a wing with smart flaps is smoother than that of a wing with conventional flaps, and tip vortexes of the flap and wing diminish for low ground clearance. Finally, the maximum lift-to-drag ratio (L/D) is obtained for a smart wing when the angle of flap (AOF)=7.5˚ and h/c=0.3. Key Words: WIG, Smart, Ground, Effect, Flap, Vortex

Ground vortex aerodynamics under crosswind conditions

An experimental study was performed to investigate ground vortex formation under crosswind conditions using stereoscopic particle image velocimetry and in-duct total pressure measurements. The effect of velocity ratio, non-dimensional height, approaching boundary layer thickness and yaw angle are assessed using vortex strength and in-duct distortion descriptors. The flow-field is characterized by a single ground vortex which increases in strength as the velocity ratio is reduced. The vortex characteristics depend on the ground clearance with a stronger vortex observed at lower intake heights. For a high ground clearance, the vortex strength reaches a local maximum before reducing towards zero as the capture streamtube no longer interacts with the ground plane. At a low ground clearance, the vortex strength is strong enough to induce a lip separation. The approaching boundary layer thickness has no notable influence on the vortex characteristics. Reducing the intake yaw angle from a crosswind to a headwind configuration leads to a monotonic decrease in vortex strength with the data following a sin3(ψ) relationship, where ψ is the yaw angle. The distortion coefficient was also monotonic with yaw angle; however, the dependence was sin6(ψ).