Multi-hole Nozzle Research Articles

Development of diesel combustion with low cooling loss and high dispersion spray using two-dimensional optical measurements

In this study, a novel, high-efficiency, and clean combustion concept utilizing low cooling loss and high dispersion spray is proposed. The research aims to validate the objectives of this concept through spatiotemporal analysis of phenomena when key variables such as combustion chamber shape, spray parameters, and swirl are modified. This new combustion approach focuses on achieving low heat loss by using smaller nozzle diameters, multi-hole nozzles, and reduced swirl compared to conventional combustion. The combustion chamber is designed with an increased cavity diameter and an expanded taper diameter to enhance upward spray dispersion, thereby reducing fuel spray penetration into the cavity and decreasing cooling loss. This configuration reduces the fuel spray penetration in cavity, achieving a reduction in cooling heat loss. Furthermore, to increase the volume in the lower part of the combustion chamber, a corner-bottom shape is employed. Additionally, by causing spray impingement through the corner bottom shape, the strategy aimed to prevent the return of the mail injections to the central part of the combustion chamber. These parameters were evaluated using two-dimensional optical measurements, which calculated thermal flux, temperature, velocity, and KL value distributions. The impact of cavity diameter on internal cooling loss is significant, and preventing flame stagnation from a smoke perspective is crucial. An increase in taper diameter reduces squish velocity, achieving heat losses reduction, while necessitating spray dispersion into the squish area. The influence of swirl ratio on heat losses is more pronounced in the squish and taper areas than inside the cavity, necessitating consideration of flame temperature reduction within the cavity when reducing swirl ratios. The implementation of double after injection influences low heat losses and avoids flame stagnation, enabling soot reduction. The corner bottom shape combustion chamber proved effective in reducing heat losses and particulate matter (PM) at medium and high loads.

Numerical and Experimental Analysis of SNCR Installation Performance in a Power Stoker Boiler

The correct design of effective SNCR (Selective Non-Catalytic Reduction) requires solving several technological challenges. For this purpose, CFD modeling and bench tests were used. This study investigated various parameters affecting the NOx reduction rate in a WR-25 stoker boiler. The first parameter analyzed was the NSR (normalized stoichiometric ratio), with a constant urea concentration of 12.5% in the solution injected into the boiler. CFD modeling indicated that increasing the NSR significantly enhances reduction efficiency, especially between NSR 1 and 2, where the efficiency more than doubles. Bench tests confirmed this trend across all boiler power levels, showing deeper reagent penetration in the chamber at higher NSR levels. However, further doubling of NSR did not yield significant efficiency improvements, likely due to limitations in chemical mixing under reagent excess conditions. Further, it was revealed that NOx reduction efficiency decreases as boiler power increases, probably due to reduced reagent residence time at the required thermodynamic conditions. Additionally, different nozzle tip designs were tested, with multi-hole nozzles (two-hole and three-hole), showing better NOx reduction than single-hole nozzles due to improved reagent distribution. Finally, a lower urea concentration in the reagent (12%) led to better NOx reduction compared to a 32.5% concentration, likely due to improved droplet penetration and mixing with flue gases.

Evaluation of the ducted fuel injection concept for medium duty engines and multi-hole nozzles: An optical analysis

Ducted Fuel Injection (DFI) is a strategy still in development, which has proved to be effective in reducing soot emissions in compression ignition engines. It works by driving the spray, formed by a high-pressure fuel injection, through a small duct co-axial to the spray itself, which is expected to affect the mixture formation and combustion process, in turn leading to noticeable reduction in soot formation. This strategy has been mostly deployed in spray vessels or in some cases in heavy duty engines consisting of mostly 2-to-4-hole nozzle injectors. For this reason, the work here is aimed to study the potential of DFI in a medium-duty single-cylinder optical engine fueled with conventional diesel having an 8-hole nozzle injector. Two different optical techniques including OH* chemiluminescence and 2-color pyrometry have been utilized to perform the analysis regarding combustion evolution and soot formation. A parametric analysis regarding different geometrical parameters including stand-off distance, diameter and length of duct has been carried out regarding the DFI performance. Results indicate that DFI does decrease the soot emissions in the context of this study and the duct geometrical parameters influence combustion evolution and soot formation ultimately affecting the device's performance. However, the scale of soot reduction is not as high as reported in previous studies, which is limited by specific boundary conditions including combustion chamber design, piston geometry utilized in this study.

Cavitation Phenomenon and Spray Atomization in Different Types of Diesel Engine Nozzles: A Systematic Review

<div>The high-pressure common rail fuel injection system for diesel engines is one of the core technologies that need to be addressed in the automobile industry. The control of the internal flow in multi-hole injector nozzles is the key to achieve accurate control of the fuel injection and spray process. There are various types of research on cavitation phenomena currently conducted on various types of test benches, but there is no conclusive discussion. Therefore, it is to summarize these studies in order to identify the highlights of existing studies and point out their shortcomings. This article compares and analyzes the developing patterns of cavitation phenomena on four test benches through literature review and has obtained rich research data on these four types of nozzles, but they still have their own shortcomings at the same time, even with numerical simulation. Based on this, the article has conducted a detailed and critical discussion on the current research situation and completed a summary. Specifically, it mainly involves four geometry parameters, two dynamic factors, and three fuel physical property parameters. The discussion conducted can contribute to the future development of cavitation models, further improving the energy-saving and -reducing emission reduction of diesel engines.</div>

Shape/penetration analysis and comparisons of isolated spray plumes in a multi-hole Diesel spray

Fuel injection systems significantly impact the combustion process and play a key role in reducing harmful exhaust emissions in internal combustion engines. For dual-fuel (DF) engines operating in gas mode, ignition of the main fuel is typically controlled by directly injected liquid pilot fuel. Liquid pilot fuel’s initial penetration and total mass considerably impact exhaust emissions and combustion stability. We investigated the spray morphology of a multi-hole diesel fuel injector within a constant-volume spray chamber using high-speed shadowgraphy and Mie-scattering measurements. Two methodologies were employed. The first one utilized a nozzle equipped with a thimble structure to isolate a single plume. The second methodology known as plume-blocking, involved sealing the orifices of the multi-hole nozzle to generate a single-spray plume. Our findings revealed that the plume-blocking approach demonstrated greater penetration than the thimble-equipped nozzle. The rapid penetration of this method may restrict its applicability to single-spray studies. Sprays generated from this partially sealed nozzle exhibited noticeable disparities compared to an unblocked nozzle, whereas a nozzle equipped with a thimble produced similar outcomes to the standard nozzle. The orifices when sealed, modify the flow distribution within the sac volume, which consequently affects the spray characteristics. In summary, this research provides insights into the impacts of various plume isolation methods on spray morphology, thereby enhancing the understanding of spray behaviour in transient conditions by comparing plume variations and disturbances under various fuel pressure and ambient conditions.

Experimental study of hydrogen jet dynamics: Investigating free momentum and impingement phenomena

There is a growing interest in the utilization of hydrogen (H2), as a zero-carbon fuel, in internal combustion engines (ICEs). Accordingly, the primary focus of this study is to investigate low-pressure H2 jet dynamics, which play a vital role in air-fuel mixing especially in direct injection (DI) engines. High-speed z-type schlieren imaging is employed in a constant volume chamber to study the effect of nozzle geometry (single-hole, double-hole, and multi-hole), pressure ratios (PR = injection pressure (Pi)/chamber pressure (Pch)), injection angle (10°, 15°, and 20°), and injection duration (ID) on the H2 jet characteristics. Image post-processing is executed in MATLAB and Python to extract the H2 jet characteristics, including penetration and cross-sectional area. The novelty stems from the comprehensive investigation of H2 jet dynamics and impingement phenomenon under various engine-like conditions. The results indicate that apart from the fact that higher pressure ratios (PRs) improve the air-fuel mixing, the single-hole nozzle induces the fastest H2 jet penetration and the smallest cross-sectional area. Conversely, the double-hole nozzle leads to the slowest penetration and the most expansive cross-sectional area. The performance of the multi-hole nozzle falls between that of the single-hole and double-hole nozzles. Additionally, changing the injection angle results in jet-piston impingement at the periphery, leading to higher H2 concentration in those areas. This negatively affects the formation of an optimal air-fuel mixture. It is also found that changing the injection duration (ID) has no noticeable impact on the H2 jet's behavior.

A multihole nozzle controls recrystallization of high-moisture extruded maize starches: Effect of cooling die temperature

Hot extrusion is utilized for starch modification due to its high mechanical input and product output. Amylose recrystallization commences and primarily depends on intermolecular interactions after conventional extrusion. Hence, the design of a new component based on the existed extrusion system was aimed at facilitating molecular aggregation, potentially accelerating starch recrystallization. In this study, a nozzle sheet comprising 89 holes was integrated into the cooling die. The impact of the multihole nozzle on the structure and in vitro digestibility of extruded maize starches after retrogradation was examined at varying cooling die temperatures. The results showed that the nozzle-assembled extrusion system operated effectively without additional mechanical or yield losses. At 50 °C, the crystallinity of nozzle-produced starch was approximately 70 % higher than that of conventionally extruded starch, predominantly owing to the B-type allomorph of the amylose double helix. Recrystallized amylopectin was also found in these nozzle-produced starches, indicating that multihole nozzle-induced uniaxial elongational flow resulted in the rapid starch crystallization. The increased formation of recrystallized amylose led to improved molecular order in starch structures while reducing their digestibility. These findings revealed a new approach to improve starch crystallinity by incorporating a nozzle sheet in the extrusion process.

Spray Momentum Flux Novel Estimation Procedure through the Fuel Rate of Injection Using Hydrogenated Fuels with Single Hole Nozzle Diesel Injector.

Sustainable means of transport require the innovation or development of propulsive systems more respectful of the environment. Despite current criticism, modern compression-ignition engines are efficient alternatives also in light aviation and surveillance drones (such as small helicopters), as means of air transport. Currently, the improvement of the injection, air-fuel mixture formation, and combustion processes using sustainable synthetic fuels, produced from renewable raw materials or by carbon dioxide capture, is a reality. For improving the air-fuel mixture formation inside the combustion chamber, one of the key parameters is knowledge of the spray momentum flux because of its effect on the air entrainement. To measure this parameter is complex. However, the experimental determination of the fuel mass flow rate is a common procedure. The objective of this work is the proposal of a novel but robust methodology for the momentum flux estimation of fuel sprays from measurement of the rate of injection. In this work, single-hole nozzles of 115, 130, and 150 μm in diameter are studied. The implemented methodology is applied to three fuels: a diesel fuel without biodiesel, used as reference, and two sustainable synthetic fuels: a gas to liquid fuel and a hydrotreated vegetable oil. With the fuel injection rates and the simple model proposed, the spray momentum flux is estimated under different operating conditions of a common-rail injection system. The results of the spray momentum flux show a very good precision compared with those experimentally and previously obtained with similar fuels but with multihole nozzle. With the method proposed in this work, an adequate forecast of spray momentum flux is obtained in the case of not having an experimental setup that allows direct measurement of the momentum flux. This study can help investigators for fuel spray modeling with novel and renewable fuels in modern propulsive systems.

Effects of in-nozzle liquid fuel vortex cavitation on characteristics of flow and spray: Numerical research

The current work studies the dynamics of vortex cavitation under various conditions, including the pressure and orifice number, and their effects on the nozzle flow and spray characteristics using a modified cavitation model considering the swirling flow. Its validation against experimental data has demonstrated a high precision of the code in terms of vortex cavitation inside the nozzles. The higher the inlet pressure, the higher the mass flow rate and discharge coefficient, but the weaker the vortex cavitation; while the vortex cavitation intensity decreases, the discharge coefficient increases and the mass flow rate is almost constant with increasing back pressure. Moreover, under the influence of vortex cavitation, the primary jet liquid spreading angle, spray penetration, and spray volume coefficient increase first and then decrease with increasing inlet pressure; with an increase of back pressure, however, the primary jet liquid spreading angle increases, the spray penetration vice versa. Additionally, once the inner well-organized large-scale longitudinal vortices are destroyed, the vortex cavitation will not incept, which induces a larger discharge coefficient and spray penetration, but a smaller primary jet liquid spreading angle as a result. The swirling flow in the multi-hole nozzle is inhibited; hence, vortex cavitation is difficult.

Research into the Aerodynamic Attenuation of Hot-Melt Adhesive Fibers Produced by Multihole Melt-Blowing Nozzles

Air consumption in the melt-blowing process represents one of the major costs involved in the production of thin fibers. In the present work an experimental study is conducted on two multihole melt-blowing nozzles for manufacturing styrene–butadiene–styrene based hot-melt adhesive fibers in order to assess their fiber attenuation capability. With this purpose in mind, fiber diameter, fiber temperature, fiber bending, and air velocity were measured experimentally, and the steady-state quasi-one-dimensional longitudinal momentum equation of the slender fiber was integrated numerically in the nozzle postextrusion region and solved for aerodynamic force prefactor K, as it appears in Matsui’s drag coefficient correlation. A measure of fiber attenuation efficiency is proposed in terms of prefactor K and other nozzle geometrical and process operating parameters, which indicates the capacity of the nozzle to produce thin fibers with low air consumption. The results indicate that increasing nozzle air tilt angle, prefactor K, and air–polymer kinematic viscosity ratio in turn increases fiber attenuation efficiency. Working conditions are provided for each nozzle design that allow thin hot-melt-adhesive melt-blown fibers to be produced in a cost-effective manner. Furthermore, a formula is provided for estimating the melt-blown fiber attenuation rate in terms of multihole nozzle geometrical and process operating parameters. The results obtained in this work will help to reduce unnecessary energy consumption of melt-blowing equipment.

Experimental study on the temperature measurement of melt blowing fibers through use of infrared thermography

ABSTRACT The temperature of melt blowing (MB) and melt spun fibers is frequently measured using infrared thermography (IRT). However, measurements are affected by the size and curvature of the fiber and by reflected radiation from the nozzle. A procedure was developed to obtain accurate measurements of fiber temperature, which corrects fiber size, fiber curvature, and reflected radiation. This procedure is more general than the ones used so far to correct fiber temperature because it corrects the three abovementioned factors using a single correction formula, this being the first time that fiber temperature correction for reflected radiation has been accounted for. It is also more accurate because it uses the local fiber diameter to correct fiber curvature, instead of mean fiber diameter. The procedure was used to measure the temperature of MB adhesive fibers produced by two multi-hole nozzle designs, the results indicating that, in melt blowing applications, the distortion caused by fiber curvature and reflected radiation on the measurement proves to be far more significant than that caused by fiber size, while correction generally leads to an increase in fiber temperature. Considerations as to the effect of different parameters on temperature correction, as well as the quality of thermographic images, are also provided throughout the text. The conclusions emerging from this study allow more accurate temperature measurements of melt blown and melt spun fibers to be obtained.

Comparative analysis of cryoablation with singlehole and multihole nozzle in cryospray

Comparative analysis of cryoablation with singlehole and multihole nozzle in cryospray

An experimental study to characterise the role of multihole nozzle in adjuvant assisted cryospray

Cryospray is a process of skin cancer treatment in which liquid nitrogen is sprayed on the lesion to achieve necrosis. In order to achieve necrosis through cryospray, a combination of particular cooling rate and lethal temperature is required. The small aperture of single hole nozzle (SHN) and the less mass flow rate associated with it reduce the rate of heat transfer from the lesion. Moreover, the low thermal conductivity of lesion further reduces the rate of energy diffusion inside it. These limitations associated with the existing method of cryospray fail to provide complete necrosis in the lesions of size larger than 15 mm in diameter. The present study addresses these issues through the modification in the existing spraying technique, i.e. inclusion of multihole nozzle (MHN) in cryospray and administration of Magnesium Oxide (MgO) nanoparticles as an adjuvant in the lesion to increase its rate of energy diffusion. The influence of mass flow rate and the rate of evaporation of cryogen on cryoablation are analysed experimentally while changing the geometrical parameters of 6 MHNs. To quantify the necrosis, thermocouples and FLIR thermal imaging camera are used to ascertain temperature profile below and above the gel surface respectively. The crystalline nature of nanoparticles is confirmed through TEM and XRD results with a particle diameter ranging between 10 and 40 nm. A comparative study of cryoablation is carried out between nano-phantom and normal-phantom. An increase of 59%, 96% and 64% in the area of necrotic zone is observed on the surface of nano-phantom for MHNs with 5 holes and margin of 1 mm, 1.5 mm and 2 mm respectively. The radius of interacellular ice formation has increased by 5 mm at an axial depth of 2 mm for MHNs with 5 holes in the nano-phantom than that in normal-phantom due to the increase in cooling rate. It is also observed that nano-phantom achieves a lower end temperature than the normal-phantom at every thermocouple position. Among the 6 MHNs selected for the study, MHN with 5 holes and 1.5 mm margin provides the most optimised result with the ablation zone of 42 mm on the surface of gel. Thus, it can be concluded that because of the introduction of adjuvant and modification in spraying device, cryoablation outcomes have been improved both quantitatively and qualitatively. The proposed approach will increase the scope of cryospray in the treatment of larger lesions.

Experimental diesel spray characterization of the medium-duty injector with single- and multi-hole nozzle configurations under non-reacting, non-vaporizing conditions

Characteristics of diesel sprays injected through Cummins medium-duty ISB injectors were studied experimentally in an optically accessible constant-volume combustion vessel. The experiments were performed with ultra-low-sulfur diesel (ULSD) under non-reacting and non-vaporizing conditions, including different ambient gas densities (23–65 kg/m3), injection pressures (500–1,500 bar), and injection duration times (0.5–1.5 ms). The ambient temperature of the vessel was maintained at a room temperature of 313 K for all the tests. A systematic comparison was made between single-hole (SH) and multi-hole (MH) injector configurations. A plume-to-plume variation in spray penetration length was observed for various operating conditions. A substantial deviation was observed for a specific hole against the averaged plume, indicating that arbitrary selection of the plume index may result in inaccurate spray characterization of the MH injector. The penetration length of the MH injector was shorter than that of the SH injector under the same operating conditions, indicating that a spray model calibrated on SH injector data may not accurately predict the transient spray behavior of the MH injector in practical engine simulations. A square-root correlation of the spray penetration length was applied for both the SH and MH injectors. The spray penetration length and dispersion angles of the ISB SH injector were also compared with those of the heavy-duty Cummins ISX SH injector. While the ISX SH injector showed a faster penetration than the ISB SH injector, the dispersion angle was similar. The differences in spray penetration between ISB and ISX injectors followed the expected trend based on their nozzle hole diameters.

Establishing relation between in-vivo and in-vitro Cryospray experiments through thermal characteristics

Cryospray is a process of destructing cancerous lesions occurring on the skin. Cryogen is sprayed on the affected area and ablation is achieved through rapid freezing of the cell. Metabolic heat generation, blood perfusion and thermal properties of tissue affect the heat sink in the skin. However, these terms are neglected in in-vitro experiments because they are performed on the tissue phantom. So, the outcomes of such studies will only provide direction to dermatologist but cannot be used in clinical applications. Hence, in-vivo thermal analysis must be conducted in order to obtain precise values before proceeding for clinical application. Present study is an attempt to explore the difference between in-vivo and in-vitro experiments. An in-vivo experiment is performed on healthy male rats (Charles Foster rats) weighing about 150–200 g while the in-vitro experiment is performed on tissue phantom. Single freeze–thaw cycle (freezing 120 s and thawing 130 s) with a spraying distance of 18 mm is selected for both the experiments. Non-invasive thermal imaging technique is used to record the temperature profile on the surface. Cryoablation beneath the surface is estimated through thermocouples. A comparative study between customised multihole nozzle (MHN) and commercial single hole nozzle (SHN) is also conducted to analyze the impact of number of holes on cryoablation in in-vivo conditions. Data extracted through thermocouples advocates that biological factors have negligible impact on cryoablation. However, histopathological results suggest that in-vivo necrotic zone is larger than the in-vitro necrotic zone. Natural thawing is responsible for such behavior. The area of cryoablation on the surface of rat skin is 50 % larger when cryogen is sprayed through MHN as compared to SHN.

Effect of Spray-Spray Interaction on Air Entrainment Process in Diesel Spray with Multi Hole Nozzle

Effect of Spray-Spray Interaction on Air Entrainment Process in Diesel Spray with Multi Hole Nozzle

Free Stream Behavior of Hydrogen Released from a Fluidic Oscillating Nozzle

The H2 internal combustion engine (ICE) is a key technology for complete decarbonization of the transport sector. To match or exceed the power density of conventional combustion engines, H2 direct injection (DI) is essential. Therefore, new injector concepts that meet the requirements of a H2 operation have to be developed. The macroscopic free stream behavior of H2 released from an innovative fluidic oscillating nozzle is investigated and compared with that of a conventional multi-hole nozzle. This work consists of H2 flow measurements and injection tests in a constant volume chamber using the Schlieren method and is accompanied by a LES simulation. The results show that an oscillating H2 free stream has a higher penetration velocity than the individual jets of a multi-hole nozzle. This behavior can be used to inject H2 far into the combustion chamber in the vertical direction while the piston is still near bottom dead center. As soon as the oscillation of the H2 free stream starts, the spray angle increases and therefore H2 is also distributed in the horizontal direction. In this phase of the injection process, spray angles comparable to those of a multi-hole nozzle are achieved. This behavior has a positive effect on H2 homogenization, which is desirable for the combustion process.

Measurement and analysis of injection characteristics among each nozzle hole within a heavy-duty diesel engine

The mass flow rate from each injector nozzle hole of a diesel engine influences the distribution, atomization, and combustion of fuel in the chamber. Thus affecting the power, the fuel economy, and the emission quality of the diesel engine. A spray momentum flux test bench was built and used to measure the injection rate from each nozzle hole of a multi-hole nozzle in this study. Selected force sensors used for data acquisition were one of the integral parts of the set-up. The influence of the force sensors’ installed position (location in the set-up) on measured results, were analyzed and the optimum position that ensures independence of the results, determined. Additionally, the effects of injection pressure, injection pulse width and injection hole diameter on the injection characteristics were also investigated. Furthermore, in this research, the reliability and robustness of Strain sensor and Piezoelectric sensors were analyzed with regards to their response. The analysis showed that, strain sensors have weak dynamic response characteristic compared to piezoelectric sensors also, the measured result obtained from strain sensors fluctuated greatly. Piezoelectric force sensor gave a more reliable and stable measurement, comparatively. The accuracy of the results were affected by the installation position of the sensors. A distance of 16 mm (between nozzle hole exit and sensor surface) was determined to be adequate for the acquisition of reliable experimental data. As the injection pressure gets higher (during injection), the rate of mass flow increased, the average cycle-to-cycle variation coefficient and nozzle-to-nozzle variability coefficient of injection quantity decreased. Hence, improving the consistency of each cycle and the uniformity of each hole. In addition, increasing the injection pulse width decreased the average cycle-to-cycle variation coefficient. Also, nozzle-to-nozzle variability coefficient had minimal or no influence with regards to injection pressure. At 80 MPa, the uniformity of injection from the multi-hole nozzle improved significantly. In summary, the larger the hole diameters, the higher the maximum value of mass flow rate and the fuel injection quantity.

Implementation of an acoustic levitator experimental setup for the investigation into drying kinetics of single droplets

In recent years, acoustic levitation has increasingly been used to examine single droplets during the drying process. Steady levitation of individual droplets in an ultrasonic field enables the contactless observation during drying. An experimental setup for a levitator is designed and used to determine the drying and levitation behavior of two different material systems. To ensure hot gas flow patterns similar to a falling droplet the ultrasonic reflector has been modified as a multi-hole nozzle through which conditioned hot air is flowing toward the levitated droplet. The surface temperature of the individual droplets is constantly measured via an infrared camera while a CMOS camera is used to track the associated volume change during the drying process. The measured temperature data and volume change from contour data can be used to determine the individual drying rate periods, calculate the heat transfer coefficients and ultimately the drying kinetics with high accuracy over a wide range of parameters. First experimental results for a TiO2 suspension and a Bentonite suspension show good repeatability and prove the suitability of the presented method for determining the drying kinetics of single suspension droplets.

Identification of significant design factors for diesel spray combustion control through comprehensive experiments with various multi-hole nozzle internal geometries

It is well known that nozzle internal geometries affect the characteristics of diesel spray and combustion. However, despite a number of studies, the effects are difficult to generalize. It is also not clear which spray features are more important for combustion than others. To investigate these subjects, a comprehensive dataset on diesel spray combustion was obtained with 20 variations of multi-hole injector nozzle. The 20 variations had different combinations of orifice diameter, orifice length, sac length and orifice hub-to-tip ratio, which cover the large range of existing production injectors. Vapor penetration, vapor width, ignition delay time, ignition distance and lift-off length were quantified using schlieren and excited-state hydroxyl radical (OH*) chemiluminescence imaging for an isolated plume emerging from these different nozzles. The experiments were conducted with Japanese diesel fuel in a constant-volume diesel spray combustion facility at Sandia National Laboratories. The results were analyzed with response surface and Lasso regression analysis to identify significant design factors for spray combustion. Orifice diameter has large effects on spray combustion. Orifice length, sac length, orifice hub-to-tip ratio and their interactions have effects on spray combustion, but each effect is smaller than the effect of orifice diameter. Vapor penetration is a significant design factor for ignition delay time, ignition distance and lift-off length, while vapor width is not. Lift-off length is well-explained by ignition distance and ignition delay time. Ignition distance should be taken into consideration as a significant design factor for lift-off length as well as ignition delay time.