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We study the recent outburst of the black hole candidate EXO 1846-031 whichwent into an outburst in 2019 after almost 34 years in quiescence. We usearchival data from Swift/XRT, MAXI/GSC, NICER/XTI and NuSTAR/FPMsatellites/instruments to study the evolution of the spectral and temporalproperties of the source during the outburst. Low energy X-ray flux of theoutburst shows multiple peaks making it a multipeak outburst. Evolving type-Cquasi-periodic oscillations (QPOs) are observed in the NICER data in the hard,hard intermediate and soft intermediate states. We use the physical TwoComponent Advective Flow (TCAF) model to analyze the combined spectra ofmultiple satellite instruments. According to the TCAF model, the accretingmatter is divided into Keplerian and sub-Keplerian parts, and the variation inthe observed spectra in different spectral states arises out of the variablecontributions of these two types of accreting matter in the total accretionrate. Studying the evolution of the accretion rates and other properties of theaccretion flow obtained from the spectral analysis, we show how the multiplepeaks in the outburst flux arises out of discontinuous supply and differentradial velocities of two types of accreting matter from the pile-up radius. Wedetect an Fe emission line at $\sim6.6$ keV in the hard and the intermediatestates in the NICER spectra. We determine the probable mass of the black holeto be $12.43^{+0.14}_{-0.03}~M_\odot$ from the spectral analysis with the TCAFmodel. We also estimate viscous time scale of the source in this outburst to be$\sim 8$ days from the peak difference of the Keplerian and sub-Keplerian massaccretion rates.

Accretion Flow Properties of EXO 1846-031 During its Multi-Peaked Outburst After Long Quiescence